--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/python3.8/site-packages/Bio/File.py	Tue Mar 18 17:55:14 2025 -0400
@@ -0,0 +1,626 @@
+# Copyright 1999 by Jeffrey Chang.  All rights reserved.
+# Copyright 2009-2018 by Peter Cock. All rights reserved.
+#
+# This file is part of the Biopython distribution and governed by your
+# choice of the "Biopython License Agreement" or the "BSD 3-Clause License".
+# Please see the LICENSE file that should have been included as part of this
+# package.
+"""Code for more fancy file handles.
+
+Bio.File defines private classes used in Bio.SeqIO and Bio.SearchIO for
+indexing files. These are not intended for direct use.
+"""
+
+import os
+import contextlib
+import itertools
+import collections.abc
+
+from abc import ABC, abstractmethod
+
+try:
+    import sqlite3
+except ImportError:
+    # May be missing if Python was compiled from source without its dependencies
+    sqlite3 = None  # type: ignore
+
+
+@contextlib.contextmanager
+def as_handle(handleish, mode="r", **kwargs):
+    r"""Context manager to ensure we are using a handle.
+
+    Context manager for arguments that can be passed to SeqIO and AlignIO read, write,
+    and parse methods: either file objects or path-like objects (strings, pathlib.Path
+    instances, or more generally, anything that can be handled by the builtin 'open'
+    function).
+
+    When given a path-like object, returns an open file handle to that path, with provided
+    mode, which will be closed when the manager exits.
+
+    All other inputs are returned, and are *not* closed.
+
+    Arguments:
+     - handleish  - Either a file handle or path-like object (anything which can be
+                    passed to the builtin 'open' function, such as str, bytes,
+                    pathlib.Path, and os.DirEntry objects)
+     - mode       - Mode to open handleish (used only if handleish is a string)
+     - kwargs     - Further arguments to pass to open(...)
+
+    Examples
+    --------
+    >>> from Bio import File
+    >>> import os
+    >>> with File.as_handle('seqs.fasta', 'w') as fp:
+    ...     fp.write('>test\nACGT')
+    ...
+    10
+    >>> fp.closed
+    True
+
+    >>> handle = open('seqs.fasta', 'w')
+    >>> with File.as_handle(handle) as fp:
+    ...     fp.write('>test\nACGT')
+    ...
+    10
+    >>> fp.closed
+    False
+    >>> fp.close()
+    >>> os.remove("seqs.fasta")  # tidy up
+
+    """
+    try:
+        with open(handleish, mode, **kwargs) as fp:
+            yield fp
+    except TypeError:
+        yield handleish
+
+
+def _open_for_random_access(filename):
+    """Open a file in binary mode, spot if it is BGZF format etc (PRIVATE).
+
+    This functionality is used by the Bio.SeqIO and Bio.SearchIO index
+    and index_db functions.
+
+    If the file is gzipped but not BGZF, a specific ValueError is raised.
+    """
+    handle = open(filename, "rb")
+    magic = handle.read(2)
+    handle.seek(0)
+
+    if magic == b"\x1f\x8b":
+        # This is a gzipped file, but is it BGZF?
+        from . import bgzf
+
+        try:
+            # If it is BGZF, we support that
+            return bgzf.BgzfReader(mode="rb", fileobj=handle)
+        except ValueError as e:
+            assert "BGZF" in str(e)
+            # Not a BGZF file after all,
+            handle.close()
+            raise ValueError(
+                "Gzipped files are not suitable for indexing, "
+                "please use BGZF (blocked gzip format) instead."
+            ) from None
+
+    return handle
+
+
+# The rest of this file defines code used in Bio.SeqIO and Bio.SearchIO
+# for indexing
+
+
+class _IndexedSeqFileProxy(ABC):
+    """Abstract base class for file format specific random access (PRIVATE).
+
+    This is subclasses in both Bio.SeqIO for indexing as SeqRecord
+    objects, and in Bio.SearchIO for indexing QueryResult objects.
+
+    Subclasses for each file format should define '__iter__', 'get'
+    and optionally 'get_raw' methods.
+    """
+
+    @abstractmethod
+    def __iter__(self):
+        """Return (identifier, offset, length in bytes) tuples.
+
+        The length can be zero where it is not implemented or not
+        possible for a particular file format.
+        """
+        raise NotImplementedError
+
+    @abstractmethod
+    def get(self, offset):
+        """Return parsed object for this entry."""
+        # Most file formats with self contained records can be handled by
+        # parsing StringIO(self.get_raw(offset).decode())
+        raise NotImplementedError
+
+    def get_raw(self, offset):
+        """Return the raw record from the file as a bytes string (if implemented).
+
+        If the key is not found, a KeyError exception is raised.
+
+        This may not have been implemented for all file formats.
+        """
+        # Should be done by each sub-class (if possible)
+        raise NotImplementedError("Not available for this file format.")
+
+
+class _IndexedSeqFileDict(collections.abc.Mapping):
+    """Read only dictionary interface to a sequential record file.
+
+    This code is used in both Bio.SeqIO for indexing as SeqRecord
+    objects, and in Bio.SearchIO for indexing QueryResult objects.
+
+    Keeps the keys and associated file offsets in memory, reads the file
+    to access entries as objects parsing them on demand. This approach
+    is memory limited, but will work even with millions of records.
+
+    Note duplicate keys are not allowed. If this happens, a ValueError
+    exception is raised.
+
+    As used in Bio.SeqIO, by default the SeqRecord's id string is used
+    as the dictionary key. In Bio.SearchIO, the query's id string is
+    used. This can be changed by supplying an optional key_function,
+    a callback function which will be given the record id and must
+    return the desired key. For example, this allows you to parse
+    NCBI style FASTA identifiers, and extract the GI number to use
+    as the dictionary key.
+
+    Note that this dictionary is essentially read only. You cannot
+    add or change values, pop values, nor clear the dictionary.
+    """
+
+    def __init__(self, random_access_proxy, key_function, repr, obj_repr):
+        """Initialize the class."""
+        # Use key_function=None for default value
+        self._proxy = random_access_proxy
+        self._key_function = key_function
+        self._repr = repr
+        self._obj_repr = obj_repr
+        self._cached_prev_record = (None, None)  # (key, record)
+        if key_function:
+            offset_iter = (
+                (key_function(key), offset, length)
+                for (key, offset, length) in random_access_proxy
+            )
+        else:
+            offset_iter = random_access_proxy
+        offsets = {}
+        for key, offset, length in offset_iter:
+            # Note - we don't store the length because I want to minimise the
+            # memory requirements. With the SQLite backend the length is kept
+            # and is used to speed up the get_raw method (by about 3 times).
+            # The length should be provided by all the current backends except
+            # SFF where there is an existing Roche index we can reuse (very fast
+            # but lacks the record lengths)
+            # assert length or format in ["sff", "sff-trim"], \
+            #       "%s at offset %i given length %r (%s format %s)" \
+            #       % (key, offset, length, filename, format)
+            if key in offsets:
+                self._proxy._handle.close()
+                raise ValueError(f"Duplicate key '{key}'")
+            else:
+                offsets[key] = offset
+        self._offsets = offsets
+
+    def __repr__(self):
+        """Return a string representation of the File object."""
+        return self._repr
+
+    def __str__(self):
+        """Create a string representation of the File object."""
+        # TODO - How best to handle the __str__ for SeqIO and SearchIO?
+        if self:
+            return f"{{{list(self.keys())[0]!r} : {self._obj_repr}(...), ...}}"
+        else:
+            return "{}"
+
+    def __len__(self):
+        """Return the number of records."""
+        return len(self._offsets)
+
+    def __iter__(self):
+        """Iterate over the keys."""
+        return iter(self._offsets)
+
+    def __getitem__(self, key):
+        """Return record for the specified key.
+
+        As an optimization when repeatedly asked to look up the same record,
+        the key and record are cached so that if the *same* record is
+        requested next time, it can be returned without going to disk.
+        """
+        if key == self._cached_prev_record[0]:
+            return self._cached_prev_record[1]
+        # Pass the offset to the proxy
+        record = self._proxy.get(self._offsets[key])
+        if self._key_function:
+            key2 = self._key_function(record.id)
+        else:
+            key2 = record.id
+        if key != key2:
+            raise ValueError(f"Key did not match ({key} vs {key2})")
+        self._cached_prev_record = (key, record)
+        return record
+
+    def get_raw(self, key):
+        """Return the raw record from the file as a bytes string.
+
+        If the key is not found, a KeyError exception is raised.
+        """
+        # Pass the offset to the proxy
+        return self._proxy.get_raw(self._offsets[key])
+
+    def close(self):
+        """Close the file handle being used to read the data.
+
+        Once called, further use of the index won't work. The sole purpose
+        of this method is to allow explicit handle closure - for example
+        if you wish to delete the file, on Windows you must first close
+        all open handles to that file.
+        """
+        self._proxy._handle.close()
+
+
+class _SQLiteManySeqFilesDict(_IndexedSeqFileDict):
+    """Read only dictionary interface to many sequential record files.
+
+    This code is used in both Bio.SeqIO for indexing as SeqRecord
+    objects, and in Bio.SearchIO for indexing QueryResult objects.
+
+    Keeps the keys, file-numbers and offsets in an SQLite database. To access
+    a record by key, reads from the offset in the appropriate file and then
+    parses the record into an object.
+
+    There are OS limits on the number of files that can be open at once,
+    so a pool are kept. If a record is required from a closed file, then
+    one of the open handles is closed first.
+    """
+
+    def __init__(
+        self,
+        index_filename,
+        filenames,
+        proxy_factory,
+        fmt,
+        key_function,
+        repr,
+        max_open=10,
+    ):
+        """Initialize the class."""
+        # TODO? - Don't keep filename list in memory (just in DB)?
+        # Should save a chunk of memory if dealing with 1000s of files.
+        # Furthermore could compare a generator to the DB on reloading
+        # (no need to turn it into a list)
+
+        if sqlite3 is None:
+            # Python was compiled without sqlite3 support
+            from Bio import MissingPythonDependencyError
+
+            raise MissingPythonDependencyError(
+                "Python was compiled without the sqlite3 module"
+            )
+        if filenames is not None:
+            filenames = list(filenames)  # In case it was a generator
+
+        # Cache the arguments as private variables
+        self._index_filename = index_filename
+        self._filenames = filenames
+        self._format = fmt
+        self._key_function = key_function
+        self._proxy_factory = proxy_factory
+        self._repr = repr
+        self._max_open = max_open
+        self._proxies = {}
+
+        # Note if using SQLite :memory: trick index filename, this will
+        # give $PWD as the relative path (which is fine).
+        self._relative_path = os.path.abspath(os.path.dirname(index_filename))
+
+        if os.path.isfile(index_filename):
+            self._load_index()
+        else:
+            self._build_index()
+
+    def _load_index(self):
+        """Call from __init__ to re-use an existing index (PRIVATE)."""
+        index_filename = self._index_filename
+        relative_path = self._relative_path
+        filenames = self._filenames
+        fmt = self._format
+        proxy_factory = self._proxy_factory
+
+        con = sqlite3.dbapi2.connect(index_filename, check_same_thread=False)
+        self._con = con
+        # Check the count...
+        try:
+            (count,) = con.execute(
+                "SELECT value FROM meta_data WHERE key=?;", ("count",)
+            ).fetchone()
+            self._length = int(count)
+            if self._length == -1:
+                con.close()
+                raise ValueError("Unfinished/partial database") from None
+
+            # use MAX(_ROWID_) to obtain the number of sequences in the database
+            # using COUNT(key) is quite slow in SQLITE
+            # (https://stackoverflow.com/questions/8988915/sqlite-count-slow-on-big-tables)
+            (count,) = con.execute("SELECT MAX(_ROWID_) FROM offset_data;").fetchone()
+            if self._length != int(count):
+                con.close()
+                raise ValueError(
+                    "Corrupt database? %i entries not %i" % (int(count), self._length)
+                ) from None
+            (self._format,) = con.execute(
+                "SELECT value FROM meta_data WHERE key=?;", ("format",)
+            ).fetchone()
+            if fmt and fmt != self._format:
+                con.close()
+                raise ValueError(
+                    f"Index file says format {self._format}, not {fmt}"
+                ) from None
+            try:
+                (filenames_relative_to_index,) = con.execute(
+                    "SELECT value FROM meta_data WHERE key=?;",
+                    ("filenames_relative_to_index",),
+                ).fetchone()
+                filenames_relative_to_index = (
+                    filenames_relative_to_index.upper() == "TRUE"
+                )
+            except TypeError:
+                # Original behaviour, assume if meta_data missing
+                filenames_relative_to_index = False
+            self._filenames = [
+                row[0]
+                for row in con.execute(
+                    "SELECT name FROM file_data ORDER BY file_number;"
+                ).fetchall()
+            ]
+            if filenames_relative_to_index:
+                # Not implicitly relative to $PWD, explicitly relative to index file
+                relative_path = os.path.abspath(os.path.dirname(index_filename))
+                tmp = []
+                for f in self._filenames:
+                    if os.path.isabs(f):
+                        tmp.append(f)
+                    else:
+                        # Would be stored with Unix / path separator, so convert
+                        # it to the local OS path separator here:
+                        tmp.append(
+                            os.path.join(relative_path, f.replace("/", os.path.sep))
+                        )
+                self._filenames = tmp
+                del tmp
+            if filenames and len(filenames) != len(self._filenames):
+                con.close()
+                raise ValueError(
+                    "Index file says %i files, not %i"
+                    % (len(self._filenames), len(filenames))
+                ) from None
+            if filenames and filenames != self._filenames:
+                for old, new in zip(self._filenames, filenames):
+                    # Want exact match (after making relative to the index above)
+                    if os.path.abspath(old) != os.path.abspath(new):
+                        con.close()
+                        if filenames_relative_to_index:
+                            raise ValueError(
+                                "Index file has different filenames, e.g. %r != %r"
+                                % (os.path.abspath(old), os.path.abspath(new))
+                            ) from None
+                        else:
+                            raise ValueError(
+                                "Index file has different filenames "
+                                "[This is an old index where any relative paths "
+                                "were relative to the original working directory]. "
+                                "e.g. %r != %r"
+                                % (os.path.abspath(old), os.path.abspath(new))
+                            ) from None
+                # Filenames are equal (after imposing abspath)
+        except sqlite3.OperationalError as err:
+            con.close()
+            raise ValueError(f"Not a Biopython index database? {err}") from None
+        # Now we have the format (from the DB if not given to us),
+        if not proxy_factory(self._format):
+            con.close()
+            raise ValueError(f"Unsupported format '{self._format}'")
+
+    def _build_index(self):
+        """Call from __init__ to create a new index (PRIVATE)."""
+        index_filename = self._index_filename
+        relative_path = self._relative_path
+        filenames = self._filenames
+        fmt = self._format
+        key_function = self._key_function
+        proxy_factory = self._proxy_factory
+        max_open = self._max_open
+        random_access_proxies = self._proxies
+
+        if not fmt or not filenames:
+            raise ValueError(
+                f"Filenames to index and format required to build {index_filename!r}"
+            )
+        if not proxy_factory(fmt):
+            raise ValueError(f"Unsupported format '{fmt}'")
+        # Create the index
+        con = sqlite3.dbapi2.connect(index_filename)
+        self._con = con
+        # print("Creating index")
+        # Sqlite PRAGMA settings for speed
+        con.execute("PRAGMA synchronous=OFF")
+        con.execute("PRAGMA locking_mode=EXCLUSIVE")
+        # Don't index the key column until the end (faster)
+        # con.execute("CREATE TABLE offset_data (key TEXT PRIMARY KEY, "
+        #             "offset INTEGER);")
+        con.execute("CREATE TABLE meta_data (key TEXT, value TEXT);")
+        con.execute("INSERT INTO meta_data (key, value) VALUES (?,?);", ("count", -1))
+        con.execute("INSERT INTO meta_data (key, value) VALUES (?,?);", ("format", fmt))
+        con.execute(
+            "INSERT INTO meta_data (key, value) VALUES (?,?);",
+            ("filenames_relative_to_index", "True"),
+        )
+        # TODO - Record the file size and modified date?
+        con.execute("CREATE TABLE file_data (file_number INTEGER, name TEXT);")
+        con.execute(
+            "CREATE TABLE offset_data (key TEXT, "
+            "file_number INTEGER, offset INTEGER, length INTEGER);"
+        )
+        count = 0
+        for file_index, filename in enumerate(filenames):
+            # Default to storing as an absolute path,
+            f = os.path.abspath(filename)
+            if not os.path.isabs(filename) and not os.path.isabs(index_filename):
+                # Since user gave BOTH filename & index as relative paths,
+                # we will store this relative to the index file even though
+                # if it may now start ../ (meaning up a level)
+                # Note for cross platform use (e.g. shared drive over SAMBA),
+                # convert any Windows slash into Unix style for rel paths.
+                f = os.path.relpath(filename, relative_path).replace(os.path.sep, "/")
+            elif (os.path.dirname(os.path.abspath(filename)) + os.path.sep).startswith(
+                relative_path + os.path.sep
+            ):
+                # Since sequence file is in same directory or sub directory,
+                # might as well make this into a relative path:
+                f = os.path.relpath(filename, relative_path).replace(os.path.sep, "/")
+                assert not f.startswith("../"), f
+            # print("DEBUG - storing %r as [%r] %r" % (filename, relative_path, f))
+            con.execute(
+                "INSERT INTO file_data (file_number, name) VALUES (?,?);",
+                (file_index, f),
+            )
+            random_access_proxy = proxy_factory(fmt, filename)
+            if key_function:
+                offset_iter = (
+                    (key_function(key), file_index, offset, length)
+                    for (key, offset, length) in random_access_proxy
+                )
+            else:
+                offset_iter = (
+                    (key, file_index, offset, length)
+                    for (key, offset, length) in random_access_proxy
+                )
+            while True:
+                batch = list(itertools.islice(offset_iter, 100))
+                if not batch:
+                    break
+                # print("Inserting batch of %i offsets, %s ... %s"
+                #       % (len(batch), batch[0][0], batch[-1][0]))
+                con.executemany(
+                    "INSERT INTO offset_data (key,file_number,offset,length) VALUES (?,?,?,?);",
+                    batch,
+                )
+                con.commit()
+                count += len(batch)
+            if len(random_access_proxies) < max_open:
+                random_access_proxies[file_index] = random_access_proxy
+            else:
+                random_access_proxy._handle.close()
+        self._length = count
+        # print("About to index %i entries" % count)
+        try:
+            con.execute(
+                "CREATE UNIQUE INDEX IF NOT EXISTS key_index ON offset_data(key);"
+            )
+        except sqlite3.IntegrityError as err:
+            self._proxies = random_access_proxies
+            self.close()
+            con.close()
+            raise ValueError(f"Duplicate key? {err}") from None
+        con.execute("PRAGMA locking_mode=NORMAL")
+        con.execute("UPDATE meta_data SET value = ? WHERE key = ?;", (count, "count"))
+        con.commit()
+        # print("Index created")
+
+    def __repr__(self):
+        return self._repr
+
+    def __contains__(self, key):
+        return bool(
+            self._con.execute(
+                "SELECT key FROM offset_data WHERE key=?;", (key,)
+            ).fetchone()
+        )
+
+    def __len__(self):
+        """Return the number of records indexed."""
+        return self._length
+        # return self._con.execute("SELECT COUNT(key) FROM offset_data;").fetchone()[0]
+
+    def __iter__(self):
+        """Iterate over the keys."""
+        for row in self._con.execute(
+            "SELECT key FROM offset_data ORDER BY file_number, offset;"
+        ):
+            yield str(row[0])
+
+    def __getitem__(self, key):
+        """Return record for the specified key."""
+        # Pass the offset to the proxy
+        row = self._con.execute(
+            "SELECT file_number, offset FROM offset_data WHERE key=?;", (key,)
+        ).fetchone()
+        if not row:
+            raise KeyError
+        file_number, offset = row
+        proxies = self._proxies
+        if file_number in proxies:
+            record = proxies[file_number].get(offset)
+        else:
+            if len(proxies) >= self._max_open:
+                # Close an old handle...
+                proxies.popitem()[1]._handle.close()
+            # Open a new handle...
+            proxy = self._proxy_factory(self._format, self._filenames[file_number])
+            record = proxy.get(offset)
+            proxies[file_number] = proxy
+        if self._key_function:
+            key2 = self._key_function(record.id)
+        else:
+            key2 = record.id
+        if key != key2:
+            raise ValueError(f"Key did not match ({key} vs {key2})")
+        return record
+
+    def get_raw(self, key):
+        """Return the raw record from the file as a bytes string.
+
+        If the key is not found, a KeyError exception is raised.
+        """
+        # Pass the offset to the proxy
+        row = self._con.execute(
+            "SELECT file_number, offset, length FROM offset_data WHERE key=?;", (key,)
+        ).fetchone()
+        if not row:
+            raise KeyError
+        file_number, offset, length = row
+        proxies = self._proxies
+        if file_number in proxies:
+            if length:
+                # Shortcut if we have the length
+                h = proxies[file_number]._handle
+                h.seek(offset)
+                return h.read(length)
+            else:
+                return proxies[file_number].get_raw(offset)
+        else:
+            # This code is duplicated from __getitem__ to avoid a function call
+            if len(proxies) >= self._max_open:
+                # Close an old handle...
+                proxies.popitem()[1]._handle.close()
+            # Open a new handle...
+            proxy = self._proxy_factory(self._format, self._filenames[file_number])
+            proxies[file_number] = proxy
+            if length:
+                # Shortcut if we have the length
+                h = proxy._handle
+                h.seek(offset)
+                return h.read(length)
+            else:
+                return proxy.get_raw(offset)
+
+    def close(self):
+        """Close any open file handles."""
+        proxies = self._proxies
+        while proxies:
+            proxies.popitem()[1]._handle.close()