zipfile —- 使用ZIP存档

源代码：Lib/zipfile.py

ZIP 文件格式是一个常用的归档与压缩标准。 这个模块提供了创建、读取、写入、添加及列出 ZIP 文件的工具。 任何对此模块的进阶使用都将需要理解此格式，其定义参见 PKZIP 应用程序笔记。

此模块目前不能处理分卷 ZIP 文件。它可以处理使用 ZIP64 扩展（超过 4 GB 的 ZIP 文件）的 ZIP 文件。它支持解密 ZIP 归档中的加密文件，但是目前不能创建一个加密的文件。解密非常慢，因为它是使用原生 Python 而不是 C 实现的。

这个模块定义了以下内容：

• exception zipfile.BadZipFile
• 为损坏的 ZIP 文件抛出的错误。

3.2 新版功能.

• exception zipfile.BadZipfile
• BadZipFile 的别名，与旧版本 Python 保持兼容性。

3.2 版后已移除.

• exception zipfile.LargeZipFile

• 当 ZIP 文件需要 ZIP64 功能但是未启用时会抛出此错误。

• class zipfile.ZipFile

• 用于读写 ZIP 文件的类。 欲了解构造函数的描述，参阅段落 ZipFile 对象。

• class zipfile.Path

• A pathlib-compatible wrapper for zip files. See sectionPath Objects for details.

3.8 新版功能.

• class zipfile.PyZipFile

• 用于创建包含 Python 库的 ZIP 归档的类。

• class zipfile.ZipInfo(filename='NoName', date_time=(1980, 1, 1, 0, 0, 0))

• 用于表示档案内一个成员信息的类。 此类的实例会由 ZipFile 对象的 getinfo() 和 infolist() 方法返回。 大多数 zipfile 模块的用户都不必创建它们，只需使用此模块所创建的实例。 filename 应当是档案成员的全名，date_time 应当是包含六个字段的描述最近修改时间的元组；这些字段的描述请参阅 ZipInfo Objects。

• zipfile.iszipfile(_filename)

• 根据文件的 Magic Number，如果 filename 是一个有效的 ZIP 文件则返回 True，否则返回 False。 filename 也可能是一个文件或类文件对象。

在 3.1 版更改: 支持文件或类文件对象。

• zipfile.ZIP_STORED

• 未被压缩的归档成员的数字常数。

• zipfile.ZIP_DEFLATED

• 常用的 ZIP 压缩方法的数字常数。需要 zlib 模块。

• zipfile.ZIP_BZIP2

• BZIP2 压缩方法的数字常数。需要 bz2 模块。

3.3 新版功能.

• zipfile.ZIP_LZMA
• LZMA 压缩方法的数字常数。需要 lzma 模块。

3.3 新版功能.

注解

ZIP 文件格式规范包括自 2001 年以来对 bzip2 压缩的支持，以及自 2006 年以来对 LZMA 压缩的支持。但是，一些工具（包括较旧的 Python 版本）不支持这些压缩方法，并且可能拒绝完全处理 ZIP 文件，或者无法提取单个文件。

参见

• PKZIP 应用程序笔记

• Phil Katz 编写的 ZIP 文件格式文档，此格式和使用的算法的创建者。

• Info-ZIP 主页

• 有关 Info-ZIP 项目的 ZIP 存档程序和开发库的信息。

ZipFile 对象

• class zipfile.ZipFile(file, mode='r', compression=ZIP_STORED, allowZip64=True, compresslevel=None, *, strict_timestamps=True)
• 打开一个 ZIP 文件，file 为一个指向文件的路径（字符串），一个类文件对象或者一个 path-like object。

形参 mode 应当为 'r' 来读取一个存在的文件，'w' 来截断并写入新的文件， 'a' 来添加到一个存在的文件，或者 'x' 来仅新建并写入新的文件。如果 mode 为 'x' 并且 file 指向已经存在的文件，则抛出 FileExistsError。如果 mode 为 'a' 且 file 为已存在的文件，则格外的文件将被加入。如果 file 不指向 ZIP 文件，之后一个新的 ZIP 归档将被追加为此文件。这是为了将 ZIP 归档添加到另一个文件（例如 python.exe）。如果 mode 为 'a' 并且文件不存在， 则会新建。如果 mode 为 'r' 或 'a'， 则文件应当可定位。

compression is the ZIP compression method to use when writing the archive,and should be ZIP_STORED, ZIP_DEFLATED,ZIP_BZIP2 or ZIP_LZMA; unrecognizedvalues will cause NotImplementedError to be raised. IfZIP_DEFLATED, ZIP_BZIP2 or ZIP_LZMA is specifiedbut the corresponding module (zlib, bz2 or lzma) is notavailable, RuntimeError is raised. The default is ZIP_STORED.

If allowZip64 is True (the default) zipfile will create ZIP files thatuse the ZIP64 extensions when the zipfile is larger than 4 GiB. If it isfalse zipfile will raise an exception when the ZIP file wouldrequire ZIP64 extensions.

The compresslevel parameter controls the compression level to use whenwriting files to the archive.When using ZIP_STORED or ZIP_LZMA it has no effect.When using ZIP_DEFLATED integers 0 through 9 are accepted(see zlib for more information).When using ZIP_BZIP2 integers 1 through 9 are accepted(see bz2 for more information).

The strict_timestamps argument, when set to False, allows tozip files older than 1980-01-01 at the cost of setting thetimestamp to 1980-01-01.Similar behavior occurs with files newer than 2107-12-31,the timestamp is also set to the limit.

If the file is created with mode 'w', 'x' or 'a' and thenclosed without adding any files to the archive, the appropriateZIP structures for an empty archive will be written to the file.

ZipFile is also a context manager and therefore supports thewith statement. In the example, myzip is closed after thewith statement's suite is finished—-even if an exception occurs:

with ZipFile('spam.zip', 'w') as myzip:
    myzip.write('eggs.txt')

3.2 新版功能: Added the ability to use ZipFile as a context manager.

在 3.3 版更改: Added support for bzip2 and lzma compression.

在 3.4 版更改: ZIP64 extensions are enabled by default.

在 3.5 版更改: Added support for writing to unseekable streams.Added support for the 'x' mode.

在 3.6 版更改: Previously, a plain RuntimeError was raised for unrecognizedcompression values.

在 3.6.2 版更改: The file parameter accepts a path-like object.

在 3.7 版更改: Add the compresslevel parameter.

3.8 新版功能: The strict_timestamps keyword-only argument

• ZipFile.close()

• Close the archive file. You must call close() before exiting your programor essential records will not be written.

• ZipFile.getinfo(name)

• Return a ZipInfo object with information about the archive membername. Calling getinfo() for a name not currently contained in thearchive will raise a KeyError.

• ZipFile.infolist()

• Return a list containing a ZipInfo object for each member of thearchive. The objects are in the same order as their entries in the actual ZIPfile on disk if an existing archive was opened.

• ZipFile.namelist()

• Return a list of archive members by name.

• ZipFile.open(name, mode='r', pwd=None, *, force_zip64=False)

• Access a member of the archive as a binary file-like object. name_can be either the name of a file within the archive or a ZipInfoobject. The _mode parameter, if included, must be 'r' (the default)or 'w'. pwd is the password used to decrypt encrypted ZIP files.

open() is also a context manager and therefore supports thewith statement:

with ZipFile('spam.zip') as myzip:
    with myzip.open('eggs.txt') as myfile:
        print(myfile.read())

With mode 'r' the file-like object(ZipExtFile) is read-only and provides the following methods:read(), readline(),readlines(), seek(),tell(), iter(), next().These objects can operate independently of the ZipFile.

With mode='w', a writable file handle is returned, which supports thewrite() method. While a writable file handle is open,attempting to read or write other files in the ZIP file will raise aValueError.

When writing a file, if the file size is not known in advance but may exceed2 GiB, pass forcezip64=True to ensure that the header format iscapable of supporting large files. If the file size is known in advance,construct a ZipInfo object with file_size set, anduse that as the _name parameter.

注解

The open(), read() and extract() methods can take a filenameor a ZipInfo object. You will appreciate this when trying to read aZIP file that contains members with duplicate names.

在 3.6 版更改: Removed support of mode='U'. Use io.TextIOWrapper for readingcompressed text files in universal newlines mode.

在 3.6 版更改: open() can now be used to write files into the archive with themode='w' option.

在 3.6 版更改: Calling open() on a closed ZipFile will raise a ValueError.Previously, a RuntimeError was raised.

• ZipFile.extract(member, path=None, pwd=None)
• Extract a member from the archive to the current working directory; member_must be its full name or a ZipInfo object. Its file information isextracted as accurately as possible. _path specifies a different directoryto extract to. member can be a filename or a ZipInfo object.pwd is the password used for encrypted files.

Returns the normalized path created (a directory or new file).

注解

If a member filename is an absolute path, a drive/UNC sharepoint andleading (back)slashes will be stripped, e.g.: ///foo/bar becomesfoo/bar on Unix, and C:\foo\bar becomes foo\bar on Windows.And all ".." components in a member filename will be removed, e.g.:../../foo../../ba..r becomes foo../ba..r. On Windows illegalcharacters (:, <, >, |, ", ?, and *)replaced by underscore (_).

在 3.6 版更改: Calling extract() on a closed ZipFile will raise aValueError. Previously, a RuntimeError was raised.

在 3.6.2 版更改: The path parameter accepts a path-like object.

• ZipFile.extractall(path=None, members=None, pwd=None)
• Extract all members from the archive to the current working directory. path_specifies a different directory to extract to. _members is optional and mustbe a subset of the list returned by namelist(). pwd is the passwordused for encrypted files.

警告

Never extract archives from untrusted sources without prior inspection.It is possible that files are created outside of path, e.g. membersthat have absolute filenames starting with "/" or filenames with twodots "..". This module attempts to prevent that.See extract() note.

在 3.6 版更改: Calling extractall() on a closed ZipFile will raise aValueError. Previously, a RuntimeError was raised.

在 3.6.2 版更改: The path parameter accepts a path-like object.

• ZipFile.printdir()

• Print a table of contents for the archive to sys.stdout.

• ZipFile.setpassword(pwd)

• Set pwd as default password to extract encrypted files.

• ZipFile.read(name, pwd=None)

• Return the bytes of the file name in the archive. name is the name of thefile in the archive, or a ZipInfo object. The archive must be open forread or append. pwd is the password used for encrypted files and, if specified,it will override the default password set with setpassword(). Callingread() on a ZipFile that uses a compression method other thanZIP_STORED, ZIP_DEFLATED, ZIP_BZIP2 orZIP_LZMA will raise a NotImplementedError. An error will alsobe raised if the corresponding compression module is not available.

在 3.6 版更改: Calling read() on a closed ZipFile will raise a ValueError.Previously, a RuntimeError was raised.

• ZipFile.testzip()
• Read all the files in the archive and check their CRC's and file headers.Return the name of the first bad file, or else return None.

在 3.6 版更改: Calling testzip() on a closed ZipFile will raise aValueError. Previously, a RuntimeError was raised.

• ZipFile.write(filename, arcname=None, compress_type=None, compresslevel=None)
• Write the file named filename to the archive, giving it the archive namearcname (by default, this will be the same as filename, but without a driveletter and with leading path separators removed). If given, compress_type_overrides the value given for the _compression parameter to the constructor forthe new entry. Similarly, compresslevel will override the constructor ifgiven.The archive must be open with mode 'w', 'x' or 'a'.

注解

Archive names should be relative to the archive root, that is, they should notstart with a path separator.

注解

If arcname (or filename, if arcname is not given) contains a nullbyte, the name of the file in the archive will be truncated at the null byte.

在 3.6 版更改: Calling write() on a ZipFile created with mode 'r' ora closed ZipFile will raise a ValueError. Previously,a RuntimeError was raised.

• ZipFile.writestr(zinfo_or_arcname, data, compress_type=None, compresslevel=None)
• Write a file into the archive. The contents is data, which may be eithera str or a bytes instance; if it is a str,it is encoded as UTF-8 first. zinfo_or_arcname is either the filename it will be given in the archive, or a ZipInfo instance. If it'san instance, at least the filename, date, and time must be given. If it's aname, the date and time is set to the current date and time.The archive must be opened with mode 'w', 'x' or 'a'.

If given, compress_type overrides the value given for the compression_parameter to the constructor for the new entry, or in the _zinfo_or_arcname(if that is a ZipInfo instance). Similarly, compresslevel willoverride the constructor if given.

注解

When passing a ZipInfo instance as the zinfo_or_arcname parameter,the compression method used will be that specified in the _compress_type_member of the given ZipInfo instance. By default, theZipInfo constructor sets this member to ZIP_STORED.

在 3.2 版更改: The compress_type argument.

在 3.6 版更改: Calling writestr() on a ZipFile created with mode 'r' ora closed ZipFile will raise a ValueError. Previously,a RuntimeError was raised.

The following data attributes are also available:

• ZipFile.filename

• Name of the ZIP file.

• ZipFile.debug

• The level of debug output to use. This may be set from 0 (the default, nooutput) to 3 (the most output). Debugging information is written tosys.stdout.

• ZipFile.comment

• The comment associated with the ZIP file as a bytes object.If assigning a comment to aZipFile instance created with mode 'w', 'x' or 'a',it should be no longer than 65535 bytes. Comments longer than this will betruncated.

Path Objects

• class zipfile.Path(root, at='')
• Construct a Path object from a root zipfile (which may be aZipFile instance or file suitable for passing tothe ZipFile constructor).

at specifies the location of this Path within the zipfile,e.g. 'dir/file.txt', 'dir/', or ''. Defaults to the empty string,indicating the root.

Path objects expose the following features of pathlib.Pathobjects:

Path objects are traversable using the / operator.

• Path.name

• The final path component.

• Path.open(*, **)

• Invoke ZipFile.open() on the current path. Acceptsthe same arguments as ZipFile.open().

• Path.iterdir()

• Enumerate the children of the current directory.

• Path.is_dir()

• Return True if the current context references a directory.

• Path.is_file()

• Return True if the current context references a file.

• Path.exists()

• Return True if the current context references a file ordirectory in the zip file.

• Path.readtext(, *_)

• Read the current file as unicode text. Positional andkeyword arguments are passed through toio.TextIOWrapper (except buffer, which isimplied by the context).

• Path.read_bytes()

• Read the current file as bytes.

PyZipFile Objects

The PyZipFile constructor takes the same parameters as theZipFile constructor, and one additional parameter, optimize.

• class zipfile.PyZipFile(file, mode='r', compression=ZIP_STORED, allowZip64=True, optimize=-1)

3.2 新版功能: The optimize parameter.

在 3.4 版更改: ZIP64 extensions are enabled by default.

Instances have one method in addition to those of ZipFile objects:

• writepy(pathname, basename='', filterfunc=None)
• Search for files *.py and add the corresponding file to thearchive.

If the optimize parameter to PyZipFile was not given or -1,the corresponding file is a *.pyc file, compiling if necessary.

If the optimize parameter to PyZipFile was 0, 1 or2, only files with that optimization level (see compile()) areadded to the archive, compiling if necessary.

If pathname is a file, the filename must end with .py, andjust the (corresponding .pyc) file is added at the top level(no path information). If pathname is a file that does not end with.py, a RuntimeError will be raised. If it is a directory,and the directory is not a package directory, then all the files.pyc are added at the top level. If the directory is apackage directory, then all *.pyc are added under the packagename as a file path, and if any subdirectories are package directories,all of these are added recursively in sorted order.

basename is intended for internal use only.

filterfunc, if given, must be a function taking a single stringargument. It will be passed each path (including each individual fullfile path) before it is added to the archive. If filterfunc returns afalse value, the path will not be added, and if it is a directory itscontents will be ignored. For example, if our test files are all eitherin test directories or start with the string test, we can use a_filterfunc to exclude them:

>>> zf = PyZipFile('myprog.zip')
>>> def notests(s):
...     fn = os.path.basename(s)
...     return (not (fn == 'test' or fn.startswith('test_')))
>>> zf.writepy('myprog', filterfunc=notests)

The writepy() method makes archives with file names likethis:

string.pyc                   # Top level name
test/__init__.pyc            # Package directory
test/testall.pyc             # Module test.testall
test/bogus/__init__.pyc      # Subpackage directory
test/bogus/myfile.pyc        # Submodule test.bogus.myfile

3.4 新版功能: The filterfunc parameter.

在 3.6.2 版更改: The pathname parameter accepts a path-like object.

在 3.7 版更改: Recursion sorts directory entries.

ZipInfo Objects

Instances of the ZipInfo class are returned by the getinfo() andinfolist() methods of ZipFile objects. Each object storesinformation about a single member of the ZIP archive.

There is one classmethod to make a ZipInfo instance for a filesystemfile:

• classmethod ZipInfo.fromfile(_filename, arcname=None, *, strict_timestamps=True)
• Construct a ZipInfo instance for a file on the filesystem, inpreparation for adding it to a zip file.

filename should be the path to a file or directory on the filesystem.

If arcname is specified, it is used as the name within the archive.If arcname is not specified, the name will be the same as filename, butwith any drive letter and leading path separators removed.

The strict_timestamps argument, when set to False, allows tozip files older than 1980-01-01 at the cost of setting thetimestamp to 1980-01-01.Similar behavior occurs with files newer than 2107-12-31,the timestamp is also set to the limit.

3.6 新版功能.

在 3.6.2 版更改: The filename parameter accepts a path-like object.

3.8 新版功能: The strict_timestamps keyword-only argument

Instances have the following methods and attributes:

• ZipInfo.is_dir()
• Return True if this archive member is a directory.

This uses the entry's name: directories should always end with /.

3.6 新版功能.

• ZipInfo.filename

• Name of the file in the archive.

• ZipInfo.date_time

• 上次修改存档成员的时间和日期。这是六个值的元组：

索引

值

0

Year (>= 1980)

1

月（1为基数）

2

月份中的日期（1为基数）

3

小时（0为基数）

4

分钟（0为基数）

5

秒（0为基数）

注解

ZIP文件格式不支持1980年以前的时间戳。

• ZipInfo.compress_type

• Type of compression for the archive member.

• ZipInfo.comment

• Comment for the individual archive member as a bytes object.

• ZipInfo.extra

• Expansion field data. The PKZIP Application Note containssome comments on the internal structure of the data contained in thisbytes object.

• ZipInfo.create_system

• System which created ZIP archive.

• ZipInfo.create_version

• PKZIP version which created ZIP archive.

• ZipInfo.extract_version

• PKZIP version needed to extract archive.

• ZipInfo.reserved

• 必须为零。

• ZipInfo.flag_bits

• ZIP 标志位。

• ZipInfo.volume

• Volume number of file header.

• ZipInfo.internal_attr

• Internal attributes.

• ZipInfo.external_attr

• External file attributes.

• ZipInfo.header_offset

• Byte offset to the file header.

• ZipInfo.CRC

• CRC-32 of the uncompressed file.

• ZipInfo.compress_size

• Size of the compressed data.

• ZipInfo.file_size

• Size of the uncompressed file.

命令行界面

The zipfile module provides a simple command-line interface to interactwith ZIP archives.

If you want to create a new ZIP archive, specify its name after the -coption and then list the filename(s) that should be included:

$ python -m zipfile -c monty.zip spam.txt eggs.txt

Passing a directory is also acceptable:

$ python -m zipfile -c monty.zip life-of-brian_1979/

If you want to extract a ZIP archive into the specified directory, usethe -e option:

$ python -m zipfile -e monty.zip target-dir/

For a list of the files in a ZIP archive, use the -l option:

$ python -m zipfile -l monty.zip

命令行选项

• -l <zipfile>
• —list <zipfile>

• List files in a zipfile.

• -c <zipfile> <source1> … <sourceN>

• —create <zipfile> <source1> … <sourceN>

• Create zipfile from source files.

• -e <zipfile> <output_dir>

• —extract <zipfile> <output_dir>

• Extract zipfile into target directory.

• -t <zipfile>

• —test <zipfile>
• Test whether the zipfile is valid or not.

Decompression pitfalls

The extraction in zipfile module might fail due to some pitfalls listed below.

From file itself

Decompression may fail due to incorrect password / CRC checksum / ZIP format orunsupported compression method / decryption.

File System limitations

Exceeding limitations on different file systems can cause decompression failed.Such as allowable characters in the directory entries, length of the file name,length of the pathname, size of a single file, and number of files, etc.

Resources limitations

The lack of memory or disk volume would lead to decompressionfailed. For example, decompression bombs (aka ZIP bomb)apply to zipfile library that can cause disk volume exhaustion.

Interruption

Interruption during the decompression, such as pressing control-C or killing thedecompression process may result in incomplete decompression of the archive.

Default behaviors of extraction

Not knowing the default extraction behaviorscan cause unexpected decompression results.For example, when extracting the same archive twice,it overwrites files without asking.