diff CSP2/bin/runSNPPipeline.py @ 0:01431fa12065

"planemo upload"
author rliterman
date Mon, 02 Dec 2024 10:40:55 -0500
parents
children 792274118b2e
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/bin/runSNPPipeline.py	Mon Dec 02 10:40:55 2024 -0500
@@ -0,0 +1,1111 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import pandas as pd
+import datetime
+from pybedtools import BedTool,helpers
+import concurrent.futures
+import time
+from Bio.Seq import Seq
+from Bio.SeqRecord import SeqRecord
+from Bio.Align import MultipleSeqAlignment
+from Bio import AlignIO
+from itertools import combinations
+import numpy as np
+import uuid
+import traceback
+import shutil
+import argparse
+
+def fetchHeaders(snpdiffs_file):
+    
+    with open(snpdiffs_file, 'r') as file:
+        top_line = file.readline().strip().split('\t')[1:]
+
+    header_cols = [item.split(':')[0] for item in top_line]
+    header_vals = [item.split(':')[1] for item in top_line]
+    
+    header_data = pd.DataFrame(columns = header_cols)
+    header_data.loc[0] = header_vals
+    header_data.loc[:, 'File_Path'] = snpdiffs_file
+      
+    return header_data
+
+def processBED(bed_rows,snpdiffs_orientation):
+    
+    bed_columns = ['Ref_Contig','Ref_Start','Ref_End','Ref_Length','Ref_Aligned',
+                   'Query_Contig','Query_Start','Query_End','Query_Length','Query_Aligned',
+                   'Perc_Iden']
+        
+    reverse_columns = ['Query_Contig','Query_Start','Query_End','Query_Length','Query_Aligned',
+                     'Ref_Contig','Ref_Start','Ref_End','Ref_Length','Ref_Aligned',
+                     'Perc_Iden']
+    
+    int_columns = ['Ref_Start', 'Ref_End', 'Ref_Length', 'Ref_Aligned',
+                'Query_Start', 'Query_End', 'Query_Length', 'Query_Aligned']
+
+    float_columns = ['Perc_Iden']
+    
+    if len(bed_rows) > 0:
+        
+        bed_df = pd.DataFrame(bed_rows, columns=bed_columns)
+        
+        # Swap columns if reversed
+        if snpdiffs_orientation == -1:
+            bed_df = bed_df[reverse_columns].copy()
+            bed_df.columns = bed_columns
+
+        # Gather covered loci
+        covered_bed_df = bed_df[(bed_df['Ref_Start'] != ".") & (bed_df['Query_Start'] != ".")].copy()
+        if covered_bed_df.shape[0] > 0:
+            for col in int_columns:
+                covered_bed_df.loc[:, col] = covered_bed_df.loc[:, col].astype(float).astype(int)
+            for col in float_columns:
+                covered_bed_df.loc[:, col] = covered_bed_df.loc[:, col].astype(float)
+        
+        return covered_bed_df
+    else:
+        return pd.DataFrame(columns=bed_columns)
+
+def processSNPs(snp_rows,snpdiffs_orientation):
+    
+    snp_columns = ['Ref_Contig','Start_Ref','Ref_Pos',
+                'Query_Contig','Start_Query','Query_Pos',
+                'Ref_Loc','Query_Loc',
+                'Ref_Start','Ref_End',
+                'Query_Start','Query_End',
+                'Ref_Base','Query_Base',
+                'Dist_to_Ref_End','Dist_to_Query_End',
+                'Ref_Aligned','Query_Aligned',
+                'Query_Direction','Perc_Iden','Cat']
+    
+    return_columns = ['Ref_Contig','Start_Ref','Ref_Pos',
+            'Query_Contig','Start_Query','Query_Pos',
+            'Ref_Loc','Query_Loc',
+            'Ref_Start','Ref_End',
+            'Query_Start','Query_End',
+            'Ref_Base','Query_Base',
+            'Dist_to_Ref_End','Dist_to_Query_End',
+            'Ref_Aligned','Query_Aligned',
+            'Perc_Iden','Cat']
+    
+    reverse_columns = ['Query_Contig','Start_Query','Query_Pos',
+                    'Ref_Contig','Start_Ref','Ref_Pos',
+                    'Query_Loc','Ref_Loc',
+                    'Query_Start','Query_End',
+                    'Ref_Start','Ref_End',
+                    'Query_Base','Ref_Base',
+                    'Dist_to_Query_End','Dist_to_Ref_End',
+                    'Query_Aligned','Ref_Aligned',
+                    'Query_Direction','Perc_Iden','Cat']
+    
+    reverse_complement = {'A':'T','T':'A','G':'C','C':'G',
+                          'a':'T','t':'A','c':'G','g':'C'}
+    
+    # Columns to convert to integer
+    int_columns = ['Start_Ref', 'Ref_Pos', 'Start_Query', 'Query_Pos',
+                'Dist_to_Ref_End', 'Dist_to_Query_End', 'Ref_Aligned', 'Query_Aligned']
+
+    # Columns to convert to float
+    float_columns = ['Perc_Iden']
+    
+    if len(snp_rows) > 0:
+        snp_df = pd.DataFrame(snp_rows, columns= snp_columns).copy()
+        
+        if snpdiffs_orientation == -1:
+            snp_df = snp_df[reverse_columns].copy()
+            snp_df.columns = snp_columns
+            
+            # Replace Query_Base and Reference_Base with reverse complement if Query_Direction is -1 and base is in ['A','T','G','C','a','c','t','g']
+            snp_df.loc[snp_df['Query_Direction'] == '-1','Query_Base'] = snp_df.loc[snp_df['Query_Direction'] == '-1','Query_Base'].apply(lambda x: reverse_complement[x] if x in reverse_complement else x)
+            snp_df.loc[snp_df['Query_Direction'] == '-1','Ref_Base'] = snp_df.loc[snp_df['Query_Direction'] == '-1','Ref_Base'].apply(lambda x: reverse_complement[x] if x in reverse_complement else x)
+        
+        for col in int_columns:
+            snp_df.loc[:, col] = snp_df.loc[:, col].astype(float).astype(int)
+        for col in float_columns:
+            snp_df.loc[:, col] = snp_df.loc[:, col].astype(float)
+        
+    else:
+        snp_df = pd.DataFrame(columns = return_columns)
+
+    return snp_df[return_columns]
+
+def swapHeader(header_data):
+            
+    raw_header_cols = [x for x in header_data.columns]
+    reverse_header_cols = [item.replace('Reference', 'temp').replace('Query', 'Reference').replace('temp', 'Query') for item in raw_header_cols]
+    reversed_header_data = header_data[reverse_header_cols].copy()
+    reversed_header_data.columns = raw_header_cols
+
+    return reversed_header_data
+    
+def parseSNPDiffs(snpdiffs_file,snpdiffs_orientation):
+
+    bed_rows = []
+    snp_rows = []
+    
+    with open(snpdiffs_file, 'r') as file:
+        lines = file.readlines()
+
+    for line in lines:
+        if line[0:2] == "#\t":
+            pass
+        elif line[0:3] == "##\t":
+            bed_rows.append(line.strip().split("\t")[1:])
+        else:
+            snp_rows.append(line.strip().split("\t"))
+
+    bed_df = processBED(bed_rows,snpdiffs_orientation)
+    snp_df = processSNPs(snp_rows,snpdiffs_orientation)
+    return (bed_df,snp_df)
+
+def calculate_total_length(bedtool):
+    return sum(len(interval) for interval in bedtool)
+
+def filterSNPs(raw_snp_df,bed_df,log_file, min_len, min_iden, ref_edge, query_edge, density_windows, max_snps):
+
+    if temp_dir != "":
+        helpers.set_tempdir(temp_dir)
+    
+    # Grab raw data    
+    total_snp_count = raw_snp_df.shape[0]
+    
+    # Get unique SNPs relative to the reference genome
+    unique_ref_snps = raw_snp_df['Ref_Loc'].unique()
+    unique_snp_count = len(unique_ref_snps)
+    
+    snp_tally_df = pd.DataFrame()
+    
+    with open(log_file,"a+") as log:
+        log.write(f"\n\t- Raw SNP + indel count: {total_snp_count}\n")
+        log.write(f"\n\t- Unique SNP positions in reference genome: {unique_snp_count}\n")
+    
+    # Set all sites to SNP
+    raw_snp_df['Filter_Cat'] = "SNP"
+    
+    # Filter out SNPs based on --min_len and --min_iden
+    reject_length = raw_snp_df.loc[(raw_snp_df['Ref_Aligned'] < min_len) & (raw_snp_df['Perc_Iden'] >= min_iden)].copy()
+    if reject_length.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Alignment Length): {reject_length.shape[0]}\n")
+        reject_length['Filter_Cat'] = "Purged_Length"
+        snp_tally_df = pd.concat([snp_tally_df,reject_length]).reset_index(drop=True)
+        
+    reject_iden = raw_snp_df.loc[(raw_snp_df['Ref_Aligned'] >= min_len) & (raw_snp_df['Perc_Iden'] < min_iden)].copy()
+    if reject_iden.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Alignment Identity): {reject_iden.shape[0]}\n")
+        reject_iden['Filter_Cat'] = "Purged_Identity"
+        snp_tally_df = pd.concat([snp_tally_df,reject_iden]).reset_index(drop=True)
+
+    reject_lenIden = raw_snp_df.loc[(raw_snp_df['Ref_Aligned'] < min_len) & (raw_snp_df['Perc_Iden'] < min_iden)].copy()
+    if reject_lenIden.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Alignment Length + Identity): {reject_lenIden.shape[0]}\n")
+        reject_lenIden['Filter_Cat'] = "Purged_LengthIdentity"
+        snp_tally_df = pd.concat([snp_tally_df,reject_lenIden]).reset_index(drop=True)
+    
+    pass_filter = raw_snp_df.loc[(raw_snp_df['Ref_Aligned'] >= min_len) & (raw_snp_df['Perc_Iden'] >= min_iden)].copy().reset_index(drop=True)
+    
+    # Invalid processing
+    reject_invalid = pass_filter[pass_filter['Cat'] == "Invalid"].copy()
+    if reject_invalid.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Invalid Base): {reject_invalid.shape[0]}\n")
+        reject_invalid['Filter_Cat'] = "Purged_Invalid"
+        snp_tally_df = pd.concat([snp_tally_df,reject_invalid]).reset_index(drop=True)
+    pass_filter = pass_filter.loc[pass_filter['Cat'] != "Invalid"].copy()
+    
+    # Indel processing
+    reject_indel = pass_filter[pass_filter['Cat'] == "Indel"].copy()
+    if reject_indel.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Indel): {reject_indel.shape[0]}\n")
+        reject_indel['Filter_Cat'] = "Purged_Indel"
+        snp_tally_df = pd.concat([snp_tally_df,reject_indel]).reset_index(drop=True)
+    pass_filter = pass_filter.loc[pass_filter['Cat'] != "Indel"].copy()
+    
+    # Check for heterozygous SNPs
+    check_heterozygous = pass_filter.groupby('Ref_Loc').filter(lambda x: x['Query_Base'].nunique() > 1)
+    if check_heterozygous.shape[0] > 0:      
+        reject_heterozygous = pass_filter.loc[pass_filter['Ref_Loc'].isin(check_heterozygous['Ref_Loc'])].copy()
+        reject_heterozygous['Filter_Cat'] = "Purged_Heterozygous"
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Heterozygotes): {reject_heterozygous.shape[0]}\n")  
+        snp_tally_df = pd.concat([snp_tally_df,reject_heterozygous]).reset_index(drop=True)
+        pass_filter = pass_filter.loc[~pass_filter['Ref_Loc'].isin(check_heterozygous['Ref_Loc'])].copy()
+   
+    # Check for duplicate SNPs and take the longest, best hit
+    check_duplicates = pass_filter.groupby('Ref_Loc').filter(lambda x: x.shape[0] > 1)
+    if check_duplicates.shape[0] > 0:
+        reject_duplicate = pass_filter.loc[pass_filter['Ref_Loc'].isin(check_duplicates['Ref_Loc'])].copy()
+        pass_filter = pass_filter.loc[~pass_filter['Ref_Loc'].isin(check_duplicates['Ref_Loc'])].copy()
+                
+        best_snp = reject_duplicate.groupby('Ref_Loc').apply(lambda x: x.sort_values(by=['Ref_Aligned', 'Perc_Iden'], ascending=[False, False]).head(1))
+        pass_filter = pd.concat([pass_filter,best_snp]).reset_index(drop=True)
+
+        dup_snps = reject_duplicate[~reject_duplicate.apply(lambda x: x in best_snp, axis=1)]        
+        dup_snps['Filter_Cat'] = "Purged_Duplicate"
+        
+        snp_tally_df = pd.concat([snp_tally_df,dup_snps]).reset_index(drop=True)
+                        
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Duplicates): {dup_snps.shape[0]}\n")    
+    
+    # Assert that Ref_Loc and Query_Loc are unique in pass_filter
+    helpers.cleanup(verbose=False,remove_all = False)
+    assert pass_filter['Ref_Loc'].nunique() == pass_filter.shape[0]
+    assert pass_filter['Query_Loc'].nunique() == pass_filter.shape[0]
+    
+    # Density filtering
+    density_locs = []
+    ref_locs = pass_filter['Ref_Loc'].tolist()
+        
+    if len(density_windows) == 0:
+        with open(log_file,"a+") as log:
+            log.write("\n\t- Density filtering disabled...\n")
+    elif len(ref_locs) > 0:
+        density_df = pd.DataFrame([item.split('/') for item in ref_locs], columns=['Ref_Contig','Ref_End'])
+        density_df['Ref_Start'] = density_df['Ref_End'].astype(float).astype(int) - 1
+        density_bed = BedTool.from_dataframe(density_df[['Ref_Contig','Ref_Start','Ref_End']])
+
+        # For each density window, remove all SNPs that fall in a window with > max_snps
+        for i in range(0,len(density_windows)):
+            window_df = density_bed.window(density_bed,c=True, w=density_windows[i]).to_dataframe()
+            problematic_windows = window_df[window_df['name'] > max_snps[i]].copy()
+            if not problematic_windows.empty:
+                temp_locs = []            
+                for _, row in problematic_windows.iterrows():
+                        purge_window_df = window_df[window_df['chrom'] == row['chrom']].copy()
+                        purge_window_df['Dist'] = abs(purge_window_df['end'] - row['end'])
+                        window_snps = purge_window_df.sort_values(by=['Dist'],ascending=True).head(row['name'])
+                        temp_locs = temp_locs + ["/".join([str(x[0]),str(x[1])]) for x in list(zip(window_snps.chrom, window_snps.end))]
+                density_locs.extend(list(set(temp_locs)))
+    
+    density_locs = list(set(density_locs))
+    reject_density = pass_filter[pass_filter['Ref_Loc'].isin(density_locs)].copy() 
+       
+    if reject_density.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Density): {reject_density.shape[0]}\n")
+        reject_density['Filter_Cat'] = "Purged_Density"
+        snp_tally_df = pd.concat([snp_tally_df,reject_density]).reset_index(drop=True)
+        pass_filter = pass_filter[~pass_filter['Ref_Loc'].isin(density_locs)].copy()
+
+    reject_query_edge = pass_filter[(pass_filter['Dist_to_Query_End'] < query_edge) & (pass_filter['Dist_to_Ref_End'] >= ref_edge)].copy()
+    reject_ref_edge = pass_filter[(pass_filter['Dist_to_Ref_End'] < ref_edge) & (pass_filter['Dist_to_Query_End'] >= query_edge)].copy()
+    reject_both_edge = pass_filter[(pass_filter['Dist_to_Query_End'] < query_edge) & (pass_filter['Dist_to_Ref_End'] < ref_edge)].copy()
+    
+    if reject_query_edge.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Query Edge): {reject_query_edge.shape[0]}\n")
+        reject_query_edge['Filter_Cat'] = "Filtered_Query_Edge"
+        snp_tally_df = pd.concat([snp_tally_df,reject_query_edge]).reset_index(drop=True)
+            
+    if reject_ref_edge.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Ref Edge): {reject_ref_edge.shape[0]}\n")
+        reject_ref_edge['Filter_Cat'] = "Filtered_Ref_Edge"
+        snp_tally_df = pd.concat([snp_tally_df,reject_ref_edge]).reset_index(drop=True)
+            
+    if reject_both_edge.shape[0] > 0:
+        with open(log_file,"a+") as log:
+            log.write(f"\t\t- Purged (Both Edge): {reject_both_edge.shape[0]}\n")
+        reject_both_edge['Filter_Cat'] = "Filtered_Both_Edge"
+        snp_tally_df = pd.concat([snp_tally_df,reject_both_edge]).reset_index(drop=True)
+        
+    pass_filter = pass_filter[(pass_filter['Dist_to_Query_End'] >= query_edge) & (pass_filter['Dist_to_Ref_End'] >= ref_edge)].copy()
+    
+    helpers.cleanup(verbose=False,remove_all = False)
+
+    assert snp_tally_df.shape[0] + pass_filter.shape[0] == total_snp_count
+    return_df = pd.concat([pass_filter,snp_tally_df]).reset_index(drop=True).sort_values(by=['Ref_Loc'])
+        
+    return return_df.drop(columns=['Cat']).rename({'Filter_Cat':'Cat'}, axis=1)
+    
+def screenSNPDiffs(snpdiffs_file,trim_name, min_cov, min_len, min_iden, ref_edge, query_edge, density_windows, max_snps,reference_id,log_directory):
+    
+    screen_start_time = time.time()
+    
+    if temp_dir != "":
+        helpers.set_tempdir(temp_dir)
+
+    # Set CSP2 variables to NA
+    csp2_screen_snps = purged_length = purged_identity = purged_invalid = purged_indel = purged_lengthIdentity = purged_duplicate = purged_het = purged_density = filtered_ref_edge = filtered_query_edge = filtered_both_edge = "NA"
+    filtered_snp_df = pd.DataFrame()
+    good_reference_bed_df = pd.DataFrame()
+    
+    # Ensure snpdiffs file exists
+    if not os.path.exists(snpdiffs_file) or not snpdiffs_file.endswith('.snpdiffs'):
+        run_failed = True       
+        sys.exit(f"Invalid snpdiffs file provided: {snpdiffs_file}")
+        
+    # Ensure header can be read in
+    try:
+        header_data = fetchHeaders(snpdiffs_file)
+        header_query = header_data['Query_ID'][0].replace(trim_name,'')
+        header_ref = header_data['Reference_ID'][0].replace(trim_name,'')
+    except:
+        run_failed = True       
+        sys.exit(f"Error reading headers from snpdiffs file: {snpdiffs_file}")
+        
+    # Check snpdiffs orientation
+    if (header_ref == reference_id):
+        snpdiffs_orientation = 1
+        query_id = header_query
+    elif (header_query == reference_id):
+        snpdiffs_orientation = -1
+        query_id = header_ref
+        header_data = swapHeader(header_data)
+    else:
+        run_failed = True       
+        sys.exit(f"Error: Reference ID not found in header of {snpdiffs_file}...")      
+
+    # Establish log file
+    log_file = f"{log_directory}/{query_id}__vs__{reference_id}.log"
+    with open(log_file,"w+") as log:
+        log.write("Reference Screening for SNP Pipeline Analysis\n")
+        log.write(f"Query Isolate: {query_id}\n")
+        log.write(f"Reference Isolate: {reference_id}\n")
+        log.write(str(datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))+"\n")
+        log.write("-------------------------------------------------------\n\n")
+        if snpdiffs_orientation == 1:
+            log.write("\t- SNPDiffs file is in the forward orientation\n")
+            log.write("-------------------------------------------------------\n\n")
+        else:
+            log.write("\t- SNPDiffs file is in the reverse orientation\n")
+            log.write("-------------------------------------------------------\n\n")
+
+    
+    # Set variables from header data
+    raw_snps = int(header_data['SNPs'][0])
+    raw_indels = int(header_data['Indels'][0])
+    raw_invalid = int(header_data['Invalid'][0])
+    
+    kmer_similarity = float(header_data['Kmer_Similarity'][0])
+    shared_kmers = int(header_data['Shared_Kmers'][0])
+    query_unique_kmers = int(header_data['Query_Unique_Kmers'][0])
+    reference_unique_kmers = int(header_data['Reference_Unique_Kmers'][0])
+    mummer_gsnps = int(header_data['gSNPs'][0])
+    mummer_gindels = int(header_data['gIndels'][0])
+    
+    query_bases = int(header_data['Query_Assembly_Bases'][0])
+    reference_bases = int(header_data['Reference_Assembly_Bases'][0])
+    
+    query_contigs = int(header_data['Query_Contig_Count'][0])
+    reference_contigs = int(header_data['Reference_Contig_Count'][0])
+    
+    raw_query_percent_aligned = float(header_data['Query_Percent_Aligned'][0])
+    raw_ref_percent_aligned = float(header_data['Reference_Percent_Aligned'][0])
+        
+    # If the reference is not covered by at least min_cov, STOP
+    if raw_ref_percent_aligned < min_cov:
+        query_percent_aligned = raw_query_percent_aligned
+        reference_percent_aligned = raw_ref_percent_aligned
+        screen_category = "Low_Coverage"
+        with open(log_file,"a+") as log:
+            log.write(f"\t- Reference genome coverage: {raw_ref_percent_aligned}% \n")
+            log.write(f"\t- Query covers less than --min_cov ({min_cov}%)...Screen halted...\n")
+            log.write("-------------------------------------------------------\n\n")
+
+    elif raw_snps + raw_indels + raw_invalid > 10000:
+        query_percent_aligned = raw_query_percent_aligned
+        reference_percent_aligned = raw_ref_percent_aligned
+        screen_category = "SNP_Cutoff"
+        with open(log_file,"a+") as log:
+            log.write(f"\t- {raw_snps} detected...\n")
+            log.write("\t- > 10,000 SNPs, indels, or invalid sites detected by MUMmer...Screen halted...\n")
+            log.write("-------------------------------------------------------\n\n")
+   
+    else:
+    
+        ##### 02: Read in BED/SNP data #####
+        with open(log_file,"a+") as log:
+                log.write("Step 1: Reading in snpdiffs BED/SNP data...")
+        try:
+            bed_df,snp_df = parseSNPDiffs(snpdiffs_file,snpdiffs_orientation)
+            
+            with open(log_file,"a+") as log:
+                log.write("Done!\n")
+                log.write("-------------------------------------------------------\n\n")
+                
+        except Exception as e:
+            run_failed = True       
+            with open(log_file,"a+") as log:
+                log.write(f"\nError reading BED/SNP data from file: {snpdiffs_file}\n{str(e)}")
+            sys.exit(f"Error reading BED/SNP data from file: {snpdiffs_file}\n{str(e)}")
+            
+        ##### 03: Filter genome overlaps #####
+        with open(log_file,"a+") as log:
+            log.write("Step 2: Filtering for short overlaps and low percent identity...")
+        
+        good_bed_df = bed_df[(bed_df['Ref_Aligned'] >= min_len) & (bed_df['Perc_Iden'] >= min_iden)].copy()
+        
+        if good_bed_df.shape[0] == 0:
+            screen_category = "Low_Quality_Coverage"
+            with open(log_file,"a+") as log:
+                log.write(f"\n\t- After filtering based on --min_len ({min_len}) and --min_iden ({min_iden}) , no valid alignments remain...Screen halted...\n")
+                log.write("-------------------------------------------------------\n\n")
+
+                
+        else:
+            # Create a BED file for alignments that pass basic QC
+            good_query_bed_df = good_bed_df[['Query_Contig','Query_Start','Query_End']].copy()
+            good_reference_bed_df = good_bed_df[['Ref_Contig','Ref_Start','Ref_End']].copy()
+            good_reference_bed_df.loc[:, 'Query_ID'] = query_id
+
+            good_query_aligned = calculate_total_length(BedTool.from_dataframe(good_query_bed_df).sort().merge())
+            good_reference_aligned = calculate_total_length(BedTool.from_dataframe(good_reference_bed_df[['Ref_Contig','Ref_Start','Ref_End']]).sort().merge())
+            
+            query_percent_aligned = (good_query_aligned / query_bases) * 100
+            reference_percent_aligned = (good_reference_aligned / reference_bases) * 100
+            
+            if reference_percent_aligned < min_cov:
+                screen_category = "Low_Quality_Coverage"
+                with open(log_file,"a+") as log:
+                    log.write(f"\n\t- Raw reference genome coverage was {raw_ref_percent_aligned}% \n")
+                    log.write(f"\t- After filtering based on --min_len ({min_len}) and --min_iden ({min_iden}), reference genome coverage was {reference_percent_aligned:.2f}% \n")
+                    log.write(f"\t- Query covers less than --min_cov ({min_cov}%) of reference after filtering...Screen halted...\n")
+                    log.write("-------------------------------------------------------\n\n")
+
+            else:
+                screen_category = "Pass"
+                with open(log_file,"a+") as log:
+                    log.write("Done!\n")
+                    log.write(f"\t- Raw reference genome coverage was {raw_ref_percent_aligned}% \n")
+                    log.write(f"\t- After filtering based on --min_len ({min_len}) and --min_iden ({min_iden}), reference genome coverage was {reference_percent_aligned:.2f}% \n")
+                    log.write("-------------------------------------------------------\n\n")
+
+            
+                # Filter SNPs
+                with open(log_file,"a+") as log:
+                    log.write("Step 3: Filtering SNPs to get final SNP distances...")
+                
+                if raw_snps == 0:
+                    csp2_screen_snps = purged_length = purged_identity = purged_lengthIdentity = purged_indel = purged_invalid = purged_duplicate = purged_het = purged_density = filtered_ref_edge = filtered_query_edge = filtered_both_edge = 0
+                    with open(log_file,"a+") as log:
+                        log.write("Done!\n")
+                        log.write("\t- No SNPs detected in MUMmer output, no filtering required\n")
+                        log.write("-------------------------------------------------------\n\n")
+
+                else:
+                    filtered_snp_df = filterSNPs(snp_df,bed_df,log_file, min_len, min_iden, ref_edge, query_edge, density_windows, max_snps)
+                    
+                    csp2_screen_snps = filtered_snp_df[filtered_snp_df.Cat == "SNP"].shape[0]
+                    purged_length = filtered_snp_df[filtered_snp_df.Cat == "Purged_Length"].shape[0]
+                    purged_identity = filtered_snp_df[filtered_snp_df.Cat == "Purged_Identity"].shape[0]
+                    purged_lengthIdentity = filtered_snp_df[filtered_snp_df.Cat == "Purged_LengthIdentity"].shape[0]
+                    purged_invalid = filtered_snp_df[filtered_snp_df.Cat == "Purged_Invalid"].shape[0]
+                    purged_indel = filtered_snp_df[filtered_snp_df.Cat == "Purged_Indel"].shape[0]
+                    purged_het = filtered_snp_df[filtered_snp_df.Cat == "Purged_Heterozygous"].shape[0]                    
+                    purged_duplicate = filtered_snp_df[filtered_snp_df.Cat == "Purged_Duplicate"].shape[0]
+                    purged_density = filtered_snp_df[filtered_snp_df.Cat == "Purged_Density"].shape[0]
+                    filtered_query_edge = filtered_snp_df[filtered_snp_df.Cat == "Filtered_Query_Edge"].shape[0]
+                    filtered_ref_edge = filtered_snp_df[filtered_snp_df.Cat == "Filtered_Ref_Edge"].shape[0]
+                    filtered_both_edge = filtered_snp_df[filtered_snp_df.Cat == "Filtered_Both_Edge"].shape[0]
+                                             
+                    # Write filtered SNP data to file
+                    snp_file = log_file.replace(".log","_SNPs.tsv")
+                    filtered_snp_df.to_csv(snp_file, sep="\t", index=False)
+                    
+                    filtered_snp_df.loc[:, 'Query_ID'] = query_id
+                    
+                    with open(log_file,"a+") as log:
+                        log.write("Done!\n")
+                        log.write(f"\t- {csp2_screen_snps} SNPs detected between {query_id} and {reference_id} after filtering\n")
+                        log.write(f"\t- Full SNP data saved to {snp_file}\n")
+                        log.write("-------------------------------------------------------\n\n")
+    
+    screen_end_time = time.time()
+    with open(log_file,"a+") as log:
+        log.write(f"Screening Time: {screen_end_time - screen_start_time:.2f} seconds\n")
+    
+    # Clean up pybedtools temp
+    helpers.cleanup(verbose=False, remove_all=False)
+    
+    return ([str(item) for item in [query_id,reference_id,screen_category,csp2_screen_snps,
+            f"{query_percent_aligned:.2f}",f"{reference_percent_aligned:.2f}",
+            query_contigs,query_bases,reference_contigs,reference_bases,
+            raw_snps,purged_length,purged_identity,purged_lengthIdentity,purged_invalid,purged_indel,purged_duplicate,purged_het,purged_density,
+            filtered_query_edge,filtered_ref_edge,filtered_both_edge,
+            kmer_similarity,shared_kmers,query_unique_kmers,reference_unique_kmers,
+            mummer_gsnps,mummer_gindels]],good_reference_bed_df,filtered_snp_df)
+
+def assessCoverage(query_id,site_list):
+    
+    if temp_dir != "":
+        helpers.set_tempdir(temp_dir)
+        
+    if len(site_list) == 0:
+        return pd.DataFrame(columns=['Ref_Loc','Query_ID','Cat'])
+    else:
+        coverage_df = pass_filter_coverage_df[pass_filter_coverage_df['Query_ID'] == query_id].copy()
+        
+        if coverage_df.shape[0] == 0:
+            uncovered_loc_df = pd.DataFrame({
+                'Ref_Loc': site_list,
+                'Query_ID': [query_id] * len(site_list),
+                'Cat': ["Uncovered"] * len(site_list)
+            })
+            return uncovered_loc_df
+        else:
+            coverage_bed = BedTool.from_dataframe(coverage_df[['Ref_Contig','Ref_Start','Ref_End']]).sort()
+            snp_bed_df = pd.DataFrame([item.split('/') for item in site_list], columns=['Ref_Contig','Ref_End'])
+            snp_bed_df['Ref_Start'] = snp_bed_df['Ref_End'].astype(float).astype(int) - 1
+            snp_bed_df['Ref_Loc'] = site_list
+            snp_bed = BedTool.from_dataframe(snp_bed_df[['Ref_Contig','Ref_Start','Ref_End','Ref_Loc']]).sort()
+            
+            # Ref_Locs from snp_bed that intersect with coverage_bed go into covered_locs, the rest go into uncovered_locs
+            covered_locs = snp_bed.intersect(coverage_bed, wa=True)
+            uncovered_locs = snp_bed.intersect(coverage_bed, v=True, wa=True)
+
+            covered_loc_df = pd.DataFrame({
+                'Ref_Loc': [snp.fields[3] for snp in covered_locs],
+                'Query_ID': [query_id] * covered_locs.count(),
+                'Cat': ["Ref_Base"] * covered_locs.count()
+            }) if covered_locs.count() > 0 else pd.DataFrame(columns=['Ref_Loc','Query_ID','Cat'])
+
+            uncovered_loc_df = pd.DataFrame({
+                'Ref_Loc': [snp.fields[3] for snp in uncovered_locs],
+                'Query_ID': [query_id] * uncovered_locs.count(),
+                'Cat': ["Uncovered"] * uncovered_locs.count()
+            }) if uncovered_locs.count() > 0 else pd.DataFrame(columns=['Ref_Loc','Query_ID','Cat'])
+            
+            # Clean up pybedtools temp
+            helpers.cleanup(verbose=False, remove_all=False)
+            
+            return pd.concat([covered_loc_df.drop_duplicates(['Ref_Loc']),uncovered_loc_df])
+
+def getPairwise(chunk, sequences, ids):
+    results = []
+    
+    for i, j in chunk:
+        seq1, seq2 = sequences[i], sequences[j]
+        actg_mask1 = np.isin(seq1, list('ACTGactg'))
+        actg_mask2 = np.isin(seq2, list('ACTGactg'))
+        cocalled_mask = actg_mask1 & actg_mask2
+        
+        snps_cocalled = np.sum(cocalled_mask)
+        snp_distance = np.sum((seq1 != seq2) & cocalled_mask)
+        
+        results.append([ids[i], ids[j], snp_distance, snps_cocalled])
+    
+    return results
+
+def parallelAlignment(alignment, chunk_size=5000):
+    sequences = [np.array(list(record.seq)) for record in alignment]
+    ids = [record.id for record in alignment]
+    pairwise_combinations = list(combinations(range(len(sequences)), 2))
+
+    # Create chunks of pairwise combinations
+    chunks = [pairwise_combinations[i:i + chunk_size] for i in range(0, len(pairwise_combinations), chunk_size)]
+
+    results = []
+    with concurrent.futures.ProcessPoolExecutor() as executor:
+        future_to_chunk = {executor.submit(getPairwise, chunk, sequences, ids): chunk for chunk in chunks}
+        for future in concurrent.futures.as_completed(future_to_chunk):
+            chunk_results = future.result()
+            results.extend(chunk_results)
+    return results
+
+def getFinalPurge(df):
+    # Returns the 'farthest along' category for a given Ref_Loc
+    if "Purged_Density" in df['Cat'].values:
+        return "Purged_Density"
+    elif "Purged_Heterozygous" in df['Cat'].values:
+        return "Purged_Heterozygous"
+    elif "Purged_Indel" in df['Cat'].values:
+        return "Purged_Indel"
+    elif "Purged_Invalid" in df['Cat'].values:
+        return "Purged_Invalid"
+    elif "Purged_Length" in df['Cat'].values:
+        return "Purged_Length"
+    else:
+        return "Purged_Identity"
+
+    
+# Read in arguments
+global run_failed
+run_failed = False
+
+start_time = time.time()
+
+parser = argparse.ArgumentParser(description='CSP2 SNP Pipeline Analysis')
+parser.add_argument('--reference_id', type=str, help='Reference Isolate')
+parser.add_argument('--output_directory', type=str, help='Output Directory')
+parser.add_argument('--log_directory', type=str, help='Log Directory')
+parser.add_argument('--snpdiffs_file', type=str, help='Path to SNPdiffs file')
+parser.add_argument('--min_cov', type=float, help='Minimum coverage')
+parser.add_argument('--min_len', type=int, help='Minimum length')
+parser.add_argument('--min_iden', type=float, help='Minimum identity')
+parser.add_argument('--ref_edge', type=int, help='Reference edge')
+parser.add_argument('--query_edge', type=int, help='Query edge')
+parser.add_argument('--density_windows', type=str, help='Density windows')
+parser.add_argument('--max_snps', type=str, help='Maximum SNPs')
+parser.add_argument('--trim_name', type=str, help='Trim name')
+parser.add_argument('--max_missing', type=float, help='Maximum missing')
+parser.add_argument('--tmp_dir', type=str, help='Temporary directory')
+parser.add_argument('--rescue', type=str, help='Rescue edge SNPs (rescue/norescue)')
+args = parser.parse_args()
+
+reference_id = args.reference_id
+output_directory = os.path.abspath(args.output_directory)
+log_directory = os.path.abspath(args.log_directory)
+log_file = f"{output_directory}/CSP2_SNP_Pipeline.log"
+snpdiffs_file = args.snpdiffs_file
+min_cov = args.min_cov
+min_len = args.min_len
+min_iden = args.min_iden
+ref_edge = args.ref_edge
+query_edge = args.query_edge
+density_windows = [int(x) for x in args.density_windows.split(",")]
+max_snps = [int(x) for x in args.max_snps.split(",")]
+trim_name = args.trim_name
+max_missing = args.max_missing
+
+# Establish log file
+with open(log_file,"w+") as log:
+    log.write("CSP2 SNP Pipeline Analysis\n")
+    log.write(f"Reference Isolate: {reference_id}\n")
+    log.write(str(datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))+"\n")
+    log.write("-------------------------------------------------------\n\n")
+    log.write("Reading in SNPDiffs files...")
+
+
+# Read in all lines and ensure each file exists
+snpdiffs_list = [line.strip() for line in open(snpdiffs_file, 'r')]
+snpdiffs_list = [line for line in snpdiffs_list if line]
+for snpdiffs_file in snpdiffs_list:
+    if not os.path.exists(snpdiffs_file):
+        run_failed = True
+        sys.exit("Error: File does not exist: " + snpdiffs_file)
+
+snpdiffs_list = list(set(snpdiffs_list))
+
+if len(snpdiffs_list) == 0:
+    run_failed = True
+    sys.exit("No SNPdiffs files provided...")
+
+with open(log_file, "a+") as log:
+    log.write("Done!\n")
+    log.write(f"\t- Read in {len(snpdiffs_list)} SNPdiffs files\n")
+    log.write("-------------------------------------------------------\n\n")
+
+global temp_dir
+if args.tmp_dir != "":
+    random_temp_id = str(uuid.uuid4())
+    temp_dir = f"{os.path.normpath(os.path.abspath(args.tmp_dir))}/{random_temp_id}"
+    try:
+        os.mkdir(temp_dir)
+        helpers.set_tempdir(temp_dir)
+    except OSError as e:
+        run_failed = True       
+        print(f"Error: Failed to create directory '{temp_dir}': {e}")
+else:
+    temp_dir = ""
+
+rescue_edge = str(args.rescue)
+if rescue_edge not in ["rescue","norescue"]:
+    with open(log_file,"a+") as log:
+        log.write(f"\t- Unexpected rescue_edge variable ('{rescue_edge}'). Not performing SNP edge rescuing (any SNPs found within {query_edge}bp of a query contig edge will be purged)...\n")
+        log.write("-------------------------------------------------------\n\n")
+    rescue_edge = "norescue"
+elif rescue_edge == "rescue":
+    with open(log_file,"a+") as log:
+        log.write(f"\t- Rescuing edge SNPs within {query_edge}bp of query contig edges if found more centrally in another query...\n")
+        log.write("-------------------------------------------------------\n\n")
+else:
+    with open(log_file,"a+") as log:
+        log.write(f"\t- Not performing SNP edge rescuing (any SNPs found within {query_edge}bp of a query contig edge will be purged)...\n")
+        log.write("-------------------------------------------------------\n\n")
+
+try:
+    # Establish output files
+    reference_screening_file = f"{output_directory}/Reference_Screening.tsv"
+    locus_category_file = f"{output_directory}/Locus_Categories.tsv"
+    query_coverage_file = f"{output_directory}/Query_Coverage.tsv"
+    raw_loclist = f"{output_directory}/snplist.txt"
+    raw_alignment = f"{output_directory}/snpma.fasta"
+    preserved_loclist = f"{output_directory}/snplist_preserved.txt"
+    preserved_alignment_file = f"{output_directory}/snpma_preserved.fasta"
+    raw_pairwise = f"{output_directory}/snp_distance_pairwise.tsv"
+    raw_matrix = f"{output_directory}/snp_distance_matrix.tsv"
+    preserved_pairwise = f"{output_directory}/snp_distance_pairwise_preserved.tsv"
+    preserved_matrix = f"{output_directory}/snp_distance_matrix_preserved.tsv"
+
+    with open(log_file,"a+") as log:
+        log.write("Screening all queries against reference...")
+    with concurrent.futures.ProcessPoolExecutor() as executor:
+        results = [executor.submit(screenSNPDiffs,snp_diff_file,trim_name, min_cov, min_len, min_iden, ref_edge, query_edge, density_windows, max_snps,reference_id,log_directory) for snp_diff_file in snpdiffs_list]
+
+    # Combine results into a dataframe
+    output_columns = ['Query_ID','Reference_ID','Screen_Category','CSP2_Screen_SNPs',
+                'Query_Percent_Aligned','Reference_Percent_Aligned',
+                'Query_Contigs','Query_Bases','Reference_Contigs','Reference_Bases',
+                'Raw_SNPs','Purged_Length','Purged_Identity','Purged_LengthIdentity','Purged_Invalid','Purged_Indel','Purged_Duplicate','Purged_Het','Purged_Density',
+                'Filtered_Query_Edge','Filtered_Ref_Edge','Filtered_Both_Edge',
+                'Kmer_Similarity','Shared_Kmers','Query_Unique_Kmers','Reference_Unique_Kmers',
+                'MUMmer_gSNPs','MUMmer_gIndels']
+
+    # Save reference screening
+    results_df = pd.DataFrame([item.result()[0] for item in results], columns = output_columns)
+    results_df.to_csv(reference_screening_file, sep="\t", index=False)
+
+    # Get reference bed dfs
+    covered_df = pd.concat([item.result()[1] for item in results])
+
+    # Get snp dfs
+    filtered_snp_df = pd.concat([item.result()[2] for item in results])
+
+    # Separate isolates that pass QC
+    pass_qc_isolates = list(set(results_df[results_df['Screen_Category'] == "Pass"]['Query_ID']))
+    fail_qc_isolates = list(set(results_df[results_df['Screen_Category'] != "Pass"]['Query_ID']))
+
+    if len(pass_qc_isolates) == 0:
+        with open(log_file,"a+") as log:
+            log.write("Done!\n")
+            log.write(f"\t- Reference screening data saved to {reference_screening_file}\n")
+            log.write(f"\t- Of {len(snpdiffs_list)} comparisons, no isolates passed QC. Pipeline cannot continue.\n")
+            log.write(f"\t- {len(fail_qc_isolates)} comparisons failed QC\n")
+            for isolate in fail_qc_isolates:
+                isolate_category = results_df[results_df['Query_ID'] == isolate]['Screen_Category'].values[0]
+                log.write(f"\t\t- {isolate}: {isolate_category}\n")
+            log.write("-------------------------------------------------------\n\n")
+        sys.exit(0)
+    else:    
+        with open(log_file,"a+") as log:
+            log.write("Done!\n")
+            log.write(f"\t- Reference screening data saved to {reference_screening_file}\n")
+            log.write(f"\t- Of {len(snpdiffs_list)} comparisons, {len(pass_qc_isolates)} covered at least {min_cov}% of the reference genome after removing poor alignments\n")
+            if len(fail_qc_isolates) > 0:
+                log.write(f"\t- {len(fail_qc_isolates)} comparisons failed QC\n")
+                for isolate in fail_qc_isolates:
+                    isolate_category = results_df[results_df['Query_ID'] == isolate]['Screen_Category'].values[0]
+                    log.write(f"\t\t- {isolate}: {isolate_category}\n")
+            log.write("-------------------------------------------------------\n\n")
+
+    with open(log_file,"a+") as log:
+        log.write(f"Compiling SNPs across {len(pass_qc_isolates)} samples...\n")
+
+    if filtered_snp_df.shape[0] == 0:
+        snp_count = 0
+        with open(log_file,"a+") as log:
+            log.write("\t- No SNPs detected across samples...Skipping to output...\n")     
+    else:
+
+        # Remove samples that failed QC
+        pass_filter_snps = filtered_snp_df[filtered_snp_df['Query_ID'].isin(pass_qc_isolates)].copy()
+        pass_filter_snp_list = list(set(pass_filter_snps['Ref_Loc']))
+        pass_filter_snp_count = len(pass_filter_snp_list)
+    
+        global pass_filter_coverage_df
+        pass_filter_coverage_df = covered_df[covered_df['Query_ID'].isin(pass_qc_isolates)].copy()
+
+        # Get SNP counts
+        snp_df = pass_filter_snps[pass_filter_snps['Cat'] == "SNP"].copy()
+        
+        if snp_df.shape[0] == 0:
+            snp_count = 0
+            with open(log_file,"a+") as log:
+                log.write(f"\t- {pass_filter_snp_count} total SNPs detected across all samples...\n")     
+                log.write("\t- No SNPs passed QC filtering in any sample...Skipping to output...\n")
+        
+        else:
+            snp_list = list(set(snp_df['Ref_Loc']))
+            snp_count = len(snp_list)
+            
+            with open(log_file,"a+") as log:
+                log.write(f"\t- {pass_filter_snp_count} total SNPs detected across all samples...\n")     
+                log.write(f"\t- {snp_count} unique SNPs passed QC filtering in at least one sample...\n")
+        
+            # Note SNPs lost irrevocably to reference edge trimming
+            ref_edge_df = pass_filter_snps[pass_filter_snps['Cat'].isin(["Filtered_Ref_Edge",'Filtered_Both_Edge'])].copy()    
+            if ref_edge_df.shape[0] > 0:        
+                with open(log_file,"a+") as log:
+                    log.write(f"\t- {ref_edge_df['Ref_Loc'].nunique()} unique SNPs were within {ref_edge}bp of a reference contig end and were not considered in any query...\n")
+        
+            # Create Ref_Base df
+            ref_base_df = snp_df[['Ref_Loc', 'Ref_Base']].copy().drop_duplicates().rename(columns = {'Ref_Base':'Query_Base'})
+            ref_base_df.loc[:,'Query_ID'] = reference_id
+            ref_base_df.loc[:,'Cat'] = "Reference_Isolate"
+            ref_base_df = ref_base_df.loc[:,['Ref_Loc','Query_ID','Query_Base','Cat']]
+            
+            # Rescue SNPs that are near the edge if they are valid SNPs in other samples
+            rescued_edge_df = pass_filter_snps[(pass_filter_snps['Cat'] == "Filtered_Query_Edge") & (pass_filter_snps['Ref_Loc'].isin(snp_list))].copy()
+            
+            if rescue_edge == "norescue":
+                with open(log_file,"a+") as log:
+                    log.write("\t- Skipping edge resucing...\n")
+            
+            elif rescued_edge_df.shape[0] > 0:
+                
+                # Remove rescued sites from pass_filter_snps
+                rescue_merge = pass_filter_snps.merge(rescued_edge_df, indicator=True, how='outer')
+                pass_filter_snps = rescue_merge[rescue_merge['_merge'] == 'left_only'].drop(columns=['_merge']).copy()            
+                
+                # Add rescued SNPs to snp_df
+                rescued_edge_df.loc[:,'Cat'] = "Rescued_SNP"    
+                snp_df = pd.concat([snp_df,rescued_edge_df]).reset_index(drop=True)
+                with open(log_file,"a+") as log:
+                    log.write(f"\t- Rescued {rescued_edge_df.shape[0]} query SNPs that fell within {query_edge}bp of the query contig edge...\n")
+            
+            else:
+                with open(log_file,"a+") as log:
+                    log.write(f"\t- No query SNPs that fell within {query_edge}bp of the query contig edge were rescued...\n")
+                                
+            # Gather base data for all valid SNPs
+            snp_base_df = snp_df[['Ref_Loc','Query_ID','Query_Base','Cat']].copy()
+            
+            # Process purged sites
+            purged_snp_df = pd.DataFrame(columns=['Ref_Loc','Query_ID','Query_Base','Cat'])
+            purged_df = pass_filter_snps[pass_filter_snps['Cat'] != "SNP"].copy()
+                    
+            if purged_df.shape[0] > 0:
+
+                # Remove rows from purged_df if the Ref_Loc/Query_ID pair is already in snp_base_df
+                purged_df = purged_df[~purged_df[['Ref_Loc','Query_ID']].apply(tuple,1).isin(snp_base_df[['Ref_Loc','Query_ID']].apply(tuple,1))].copy()
+                
+                if purged_df.shape[0] > 0:
+
+                    # Get purged SNPs where no query has a valid SNP
+                    non_snp_df = purged_df[~purged_df['Ref_Loc'].isin(snp_list)].copy()
+                    if non_snp_df.shape[0] > 0:
+                        non_snp_merge = purged_df.merge(non_snp_df, indicator=True, how='outer')
+                        purged_df = non_snp_merge[non_snp_merge['_merge'] == 'left_only'].drop(columns=['_merge']).copy()
+
+                        with open(log_file,"a+") as log:
+                            log.write(f"\t- {len(list(set(non_snp_df['Ref_Loc'])))} unique SNPs were purged in all queries they were found in, and were not considered in the final dataset...\n")
+            
+            if purged_df.shape[0] > 0:
+
+                purged_snp_df = purged_df[['Ref_Loc','Query_ID']].copy().drop_duplicates()
+                purged_snp_df.loc[:, 'Query_Base'] = "N"
+                final_purge_df = purged_df.groupby(['Ref_Loc','Query_ID']).apply(getFinalPurge).reset_index().rename(columns={0:'Cat'})
+                purged_snp_df = purged_snp_df.merge(final_purge_df, on=['Ref_Loc','Query_ID'], how='inner')
+
+            # Genomic positions that do not occur- in the SNP data are either uncovered or match the reference base
+            missing_df = pd.DataFrame(columns=['Ref_Loc','Query_ID','Query_Base','Cat'])
+
+            covered_snps = pd.concat([snp_base_df,purged_snp_df]).copy()
+            ref_loc_sets = covered_snps.groupby('Query_ID')['Ref_Loc'].agg(set).to_dict()
+            isolates_with_missing = [isolate for isolate in pass_qc_isolates if len(set(snp_list) - ref_loc_sets.get(isolate, set())) > 0]
+            
+            uncovered_df = pd.DataFrame()
+            
+            if isolates_with_missing:
+                isolate_data = [(isolate, list(set(snp_list) - ref_loc_sets.get(isolate, set()))) for isolate in isolates_with_missing]        
+                
+                with concurrent.futures.ProcessPoolExecutor() as executor:
+                    results = [executor.submit(assessCoverage, query, sites) for query, sites in isolate_data]
+                    coverage_dfs = [result.result() for result in concurrent.futures.as_completed(results)]
+
+                coverage_df = pd.concat(coverage_dfs)
+                covered_df = coverage_df[coverage_df['Cat'] == 'Ref_Base']
+                uncovered_df = coverage_df[coverage_df['Cat'] == 'Uncovered']
+                
+                if not uncovered_df.empty:
+                    uncovered_df.loc[:, 'Query_Base'] = "?"
+                    missing_df = pd.concat([missing_df, uncovered_df[['Ref_Loc', 'Query_ID', 'Query_Base', 'Cat']]])
+        
+                if not covered_df.empty:
+                    ref_base_snp_df = covered_df.merge(ref_base_df[['Ref_Loc', 'Query_Base']], on='Ref_Loc', how='left')
+                    missing_df = pd.concat([missing_df, ref_base_snp_df[['Ref_Loc', 'Query_ID', 'Query_Base', 'Cat']]])        
+            
+            with open(log_file,"a+") as log:
+                log.write("\t- Processed coverage information...\n")
+
+            final_snp_df = pd.concat([snp_base_df,purged_snp_df,missing_df,ref_base_df]).sort_values(by=['Ref_Loc','Query_ID']).reset_index(drop=True)
+            snp_counts = final_snp_df.groupby('Query_ID')['Ref_Loc'].count().reset_index().rename(columns={'Ref_Loc':'SNP_Count'})
+
+            # Assert that all snp_counts == snp_count
+            assert snp_counts['SNP_Count'].nunique() == 1
+            assert snp_counts['SNP_Count'].values[0] == snp_count
+
+            # Get locus coverage stats        
+            snp_coverage_df = final_snp_df[final_snp_df['Cat'].isin(['SNP','Rescued_SNP'])].groupby('Ref_Loc')['Query_ID'].count().reset_index().rename(columns={'Query_ID':'SNP_Count'})
+            ref_base_coverage_df = final_snp_df[final_snp_df['Cat'].isin(["Ref_Base","Reference_Isolate"])].groupby('Ref_Loc')['Query_ID'].count().reset_index().rename(columns={'Query_ID':'Ref_Base_Count'}) 
+            
+            if uncovered_df.shape[0] > 0:
+                uncovered_count_df = final_snp_df[final_snp_df['Cat'] == "Uncovered"].groupby('Ref_Loc')['Query_ID'].count().reset_index().rename(columns={'Query_ID':'Uncovered_Count'}).copy()
+            else:
+                uncovered_count_df = pd.DataFrame(columns=['Ref_Loc','Uncovered_Count'])
+
+            possible_purged_cols = ['Purged_Length','Purged_Identity','Purged_Invalid','Purged_Indel','Purged_Heterozygous','Purged_Density']
+            if purged_snp_df.shape[0] > 0:
+                purged_count_df = final_snp_df[final_snp_df['Cat'].isin(possible_purged_cols)].groupby('Ref_Loc')['Query_ID'].count().reset_index().rename(columns={'Query_ID':'Purged_Count'}).copy()
+            else:
+                purged_count_df = pd.DataFrame(columns=['Ref_Loc','Purged_Count'])
+
+            locus_coverage_df = snp_coverage_df.merge(ref_base_coverage_df, how='outer', on='Ref_Loc').merge(uncovered_count_df, how='outer', on='Ref_Loc').merge(purged_count_df, how='outer', on='Ref_Loc').fillna(0)
+            locus_coverage_df.loc[:, ['SNP_Count','Ref_Base_Count','Uncovered_Count','Purged_Count']] = locus_coverage_df.loc[:, ['SNP_Count','Ref_Base_Count','Uncovered_Count','Purged_Count']].astype(int)
+            locus_coverage_df['Missing_Ratio'] = ((locus_coverage_df['Uncovered_Count'] + locus_coverage_df['Purged_Count']) / (1+len(pass_qc_isolates))) * 100
+            locus_coverage_df.to_csv(locus_category_file, sep="\t", index=False)
+            
+            # Get isolate coverage stats
+            min_isolate_cols = ['Query_ID','SNP','Ref_Base','Percent_Missing','Purged','Uncovered','Rescued_SNP','Purged_Ref_Edge']
+            isolate_coverage_df = final_snp_df.groupby('Query_ID')['Cat'].value_counts().unstack().fillna(0).astype(float).astype(int).reset_index().drop(columns=['Reference_Isolate'])
+            isolate_coverage_df.loc[isolate_coverage_df['Query_ID'] == reference_id, 'Ref_Base'] = snp_count
+            
+            if "Rescued_SNP" not in isolate_coverage_df.columns.tolist():
+                isolate_coverage_df.loc[:,'Rescued_SNP'] = 0
+            isolate_coverage_df['SNP'] = isolate_coverage_df['SNP'] + isolate_coverage_df['Rescued_SNP']
+            
+            for col in ['Uncovered'] + possible_purged_cols:
+                if col not in isolate_coverage_df.columns.tolist():
+                    isolate_coverage_df.loc[:,col] = 0            
+                
+            isolate_coverage_df['Purged'] = isolate_coverage_df[possible_purged_cols].sum(axis=1)
+
+            isolate_coverage_df['Percent_Missing'] = (isolate_coverage_df['Uncovered'] + isolate_coverage_df['Purged'])/(isolate_coverage_df['Uncovered'] + isolate_coverage_df['Purged'] + isolate_coverage_df['Ref_Base'] + isolate_coverage_df['SNP']) * 100
+            
+            isolate_coverage_df.loc[:,'Purged_Ref_Edge'] = 0
+            if ref_edge_df.shape[0] > 0:
+                isolate_coverage_df.loc[isolate_coverage_df['Query_ID'] == reference_id, 'Purged_Ref_Edge'] = ref_edge_df['Ref_Loc'].nunique()
+            
+            isolate_coverage_df = isolate_coverage_df[min_isolate_cols + possible_purged_cols].sort_values(by = 'Percent_Missing',ascending = False).reset_index(drop=True)
+            isolate_coverage_df.to_csv(query_coverage_file, sep="\t", index=False)
+            
+            with open(log_file,"a+") as log:
+                log.write(f"\t- SNP coverage information: {locus_category_file}\n")
+                log.write(f"\t- Query coverage information: {query_coverage_file}\n")
+                log.write("-------------------------------------------------------\n\n")
+            
+            with open(log_file,"a+") as log:
+                log.write("Processing alignment data...")
+
+            alignment_df = final_snp_df[['Query_ID','Ref_Loc','Query_Base']].copy().rename(columns={'Query_Base':'Base'}).pivot(index='Query_ID', columns='Ref_Loc', values='Base')
+            csp2_ordered = alignment_df.columns
+
+            with open(raw_loclist,"w+") as loclist:
+                loclist.write("\n".join(csp2_ordered)+"\n")
+            
+            seq_records = [SeqRecord(Seq(''.join(row)), id=query,description='') for query,row in alignment_df.iterrows()]
+            
+            alignment = MultipleSeqAlignment(seq_records)
+            AlignIO.write(alignment,raw_alignment,"fasta")
+
+            with open(log_file,"a+") as log:
+                log.write("Done!\n")
+                log.write(f"\t- Saved alignment of {snp_count} SNPs to {raw_alignment}\n")
+                log.write(f"\t- Saved ordered loc list to {raw_loclist}\n")
+            
+            if max_missing == float(100):
+                locs_pass_missing = csp2_ordered
+                preserved_alignment = alignment
+                
+                AlignIO.write(preserved_alignment,preserved_alignment_file,"fasta")
+                with open(preserved_loclist,"w+") as loclist:
+                    loclist.write("\n".join(csp2_ordered)+"\n")
+                
+                with open(log_file,"a+") as log:
+                    log.write("Skipping SNP preservation step...\n")
+                    log.write(f"\t- Saved duplicate alignment to {preserved_alignment_file}\n")
+                    log.write(f"\t- Saved duplicate ordered loc list to {preserved_loclist}\n")
+            else:
+                with open(log_file,"a+") as log:
+                    log.write(f"\t- Preserving SNPs with at most {max_missing}% missing data...\n")
+                
+                # Parse missing data
+                locs_pass_missing = list(set(locus_coverage_df[locus_coverage_df['Missing_Ratio'] <= max_missing]['Ref_Loc']))
+                
+                if len(locs_pass_missing) == 0:
+                    with open(log_file,"a+") as log:
+                        log.write(f"\t- Of {snp_count} SNPs, no SNPs pass the {max_missing}% missing data threshold...\n")
+                        log.write("-------------------------------------------------------\n\n")
+                else:
+                    preserved_alignment_df = alignment_df[locs_pass_missing].copy()
+                    
+                    preserved_ordered = preserved_alignment_df.columns
+                    with open(preserved_loclist,"w+") as loclist:
+                        loclist.write("\n".join(preserved_ordered)+"\n")
+                    
+                    seq_records = [SeqRecord(Seq(''.join(row)), id=query,description='') for query,row in preserved_alignment_df.iterrows()]
+                    preserved_alignment = MultipleSeqAlignment(seq_records)
+                    AlignIO.write(preserved_alignment,preserved_alignment_file,"fasta")
+                    with open(log_file,"a+") as log:
+                        log.write(f"\t- Of {snp_count} SNPs, {len(locs_pass_missing)} SNPs pass the {max_missing}% missing data threshold...\n")
+                        log.write(f"\t- Saved preserved alignment to {preserved_alignment_file}\n")
+                        log.write(f"\t- Saved preserved ordered loc list to {preserved_loclist}\n")
+                        log.write("-------------------------------------------------------\n\n")
+
+    with open(log_file,"a+") as log:
+        log.write("Processing pairwise comparisons files...")
+
+    # Get pairwise comparisons between all pass_qc_isolates and reference_id
+    pairwise_combinations = [sorted(x) for x in list(combinations([reference_id] + pass_qc_isolates, 2))]
+
+    if snp_count == 0:
+        pairwise_df = pd.DataFrame([(pairwise[0], pairwise[1], 0,np.nan) for pairwise in pairwise_combinations],columns = ['Query_1','Query_2','SNP_Distance','SNPs_Cocalled'])
+        preserved_pairwise_df = pairwise_df.copy()
+        
+        pairwise_df.to_csv(raw_pairwise, sep="\t", index=False)
+        preserved_pairwise_df.to_csv(preserved_pairwise, sep="\t", index=False)
+        
+        # Create matrix
+        idx = sorted(set(pairwise_df['Query_1']).union(pairwise_df['Query_2']))
+        mirrored_distance_df = pairwise_df.pivot(index='Query_1', columns='Query_2', values='SNP_Distance').reindex(index=idx, columns=idx).fillna(0, downcast='infer').pipe(lambda x: x+x.values.T).applymap(lambda x: format(x, '.0f'))
+        mirrored_distance_df.index.name = ''
+        mirrored_distance_df.to_csv(raw_matrix,sep="\t")
+        mirrored_distance_df.to_csv(preserved_matrix,sep="\t")
+
+    else:
+        raw_distance_results = parallelAlignment(alignment)
+        raw_pairwise_df = pd.DataFrame(raw_distance_results, columns=['Query_1', 'Query_2', 'SNP_Distance', 'SNPs_Cocalled'])
+        raw_pairwise_df.to_csv(raw_pairwise, sep="\t", index=False)
+
+        if len(locs_pass_missing) == snp_count:
+            preserved_pairwise_df = raw_pairwise_df.copy()
+            preserved_pairwise_df.to_csv(preserved_pairwise, sep="\t", index=False)
+        elif len(locs_pass_missing) == 0:
+            preserved_pairwise_df = pd.DataFrame([(pairwise[0], pairwise[1], 0,np.nan) for pairwise in pairwise_combinations],columns = ['Query_1','Query_2','SNP_Distance','SNPs_Cocalled'])
+            preserved_pairwise_df.to_csv(preserved_pairwise, sep="\t", index=False)
+        else:
+            preserved_distance_results = parallelAlignment(preserved_alignment)
+            preserved_pairwise_df = pd.DataFrame(preserved_distance_results, columns=['Query_1', 'Query_2', 'SNP_Distance', 'SNPs_Cocalled'])
+            preserved_pairwise_df.to_csv(preserved_pairwise, sep="\t", index=False)
+    
+        # Create matrix
+        idx = sorted(set(raw_pairwise_df['Query_1']).union(raw_pairwise_df['Query_2']))
+        mirrored_distance_df = raw_pairwise_df.pivot(index='Query_1', columns='Query_2', values='SNP_Distance').reindex(index=idx, columns=idx).fillna(0, downcast='infer').pipe(lambda x: x+x.values.T).applymap(lambda x: format(x, '.0f'))
+        mirrored_distance_df.index.name = ''
+        mirrored_distance_df.to_csv(raw_matrix,sep="\t")
+        
+        idx = sorted(set(preserved_pairwise_df['Query_1']).union(preserved_pairwise_df['Query_2']))
+        mirrored_distance_df = preserved_pairwise_df.pivot(index='Query_1', columns='Query_2', values='SNP_Distance').reindex(index=idx, columns=idx).fillna(0, downcast='infer').pipe(lambda x: x+x.values.T).applymap(lambda x: format(x, '.0f'))
+        mirrored_distance_df.index.name = ''
+        mirrored_distance_df.to_csv(preserved_matrix,sep="\t")
+
+    # Clean up pybedtools temp
+    helpers.cleanup(verbose=False,remove_all = False)
+
+    end_time = time.time()
+    with open(log_file,"a+") as log:
+        log.write("Done!\n")
+        if snp_count == 0:
+            log.write(f"\t- No SNPs detected, zeroed pairwise distance files saved to {raw_pairwise}/{preserved_pairwise}/{raw_matrix}/{preserved_matrix}\n")
+        else:
+            log.write(f"\t- Saved raw pairwise distances to {raw_pairwise}\n")
+            log.write(f"\t- Saved raw pairwise matrix to {raw_matrix}\n")
+
+            if max_missing == float(100):
+                log.write("Skipped SNP preservation step...\n")
+                log.write(f"\t- Saved duplicated preserved pairwise distances to {preserved_pairwise}\n")
+                log.write(f"\t- Saved duplicated preserved pairwise matrix to {preserved_matrix}\n")
+            elif len(locs_pass_missing) == 0:
+                log.write(f"\t- No SNPs passed the {max_missing}% missing data threshold, zeroed pairwise distance files saved to {preserved_pairwise}/{preserved_matrix}\n")
+            else:
+                log.write(f"\t- Saved preserved pairwise distances to {preserved_pairwise}\n")
+                log.write(f"\t- Saved preserved pairwise matrix to {preserved_matrix}\n")
+        log.write(f"Total Time: {end_time - start_time:.2f} seconds\n")
+        log.write("-------------------------------------------------------\n\n")
+
+except:
+    run_failed = True
+    print("Exception occurred:\n", traceback.format_exc())
+finally:
+    helpers.cleanup(verbose=False, remove_all=False)
+    if temp_dir != "":
+        shutil.rmtree(temp_dir)
+    if run_failed:
+        sys.exit(1)
\ No newline at end of file