13.5. zipfile — Work with ZIP archives — Python 3.3.5 documentation

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# 13.5. `zipfile` — Work with ZIP archives

Source code: Lib/zipfile.py

The ZIP file format is a common archive and compression standard. This module provides tools to create, read, write, append, and list a ZIP file. Any advanced use of this module will require an understanding of the format, as defined in PKZIP Application Note.

This module does not currently handle multi-disk ZIP files. It can handle ZIP files that use the ZIP64 extensions (that is ZIP files that are more than 4 GiB in size). It supports decryption of encrypted files in ZIP archives, but it currently cannot create an encrypted file. Decryption is extremely slow as it is implemented in native Python rather than C.

The module defines the following items:

exception `zipfile.` `BadZipFile`

  The error raised for bad ZIP files.

  New in version 3.2.

exception `zipfile.` `BadZipfile`

  Alias of `BadZipFile`, for compatibility with older Python versions.

  Deprecated since version 3.2.

exception `zipfile.` `LargeZipFile`

  The error raised when a ZIP file would require ZIP64 functionality but that has not been enabled.

class `zipfile.` `ZipFile`

  The class for reading and writing ZIP files. See section ZipFile Objects for constructor details.

class `zipfile.` `PyZipFile`

  Class for creating ZIP archives containing Python libraries.

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

  Class used to represent information about a member of an archive. Instances of this class are returned by the `getinfo()` and `infolist()` methods of `ZipFile` objects. Most users of the `zipfile` module will not need to create these, but only use those created by this module. filename should be the full name of the archive member, and date_time should be a tuple containing six fields which describe the time of the last modification to the file; the fields are described in section ZipInfo Objects.

`zipfile.` `is_zipfile`(filename)

  Returns `True` if filename is a valid ZIP file based on its magic number, otherwise returns `False`. filename may be a file or file-like object too.

  Changed in version 3.1: Support for file and file-like objects.

`zipfile.` `ZIP_STORED`

  The numeric constant for an uncompressed archive member.

`zipfile.` `ZIP_DEFLATED`

  The numeric constant for the usual ZIP compression method. This requires the `zlib` module.

`zipfile.` `ZIP_BZIP2`

  The numeric constant for the BZIP2 compression method. This requires the `bz2` module.

  New in version 3.3.

`zipfile.` `ZIP_LZMA`

  The numeric constant for the LZMA compression method. This requires the `lzma` module.

  New in version 3.3.

  Note

  The ZIP file format specification has included support for bzip2 compression since 2001, and for LZMA compression since 2006. However, some tools (including older Python releases) do not support these compression methods, and may either refuse to process the ZIP file altogether, or fail to extract individual files.

See also

PKZIP Application Note
  Documentation on the ZIP file format by Phil Katz, the creator of the format and algorithms used.
Info-ZIP Home Page
  Information about the Info-ZIP project’s ZIP archive programs and development libraries.

## 13.5.1. ZipFile Objects

class `zipfile.` `ZipFile`(file, mode='r', compression=ZIP_STORED, allowZip64=False)

  Open a ZIP file, where file can be either a path to a file (a string) or a file-like object. The mode parameter should be `'r'` to read an existing file, `'w'` to truncate and write a new file, or `'a'` to append to an existing file. If mode is `'a'` and file refers to an existing ZIP file, then additional files are added to it. If file does not refer to a ZIP file, then a new ZIP archive is appended to the file. This is meant for adding a ZIP archive to another file (such as `python.exe`). If mode is `a` and the file does not exist at all, it is created. compression is the ZIP compression method to use when writing the archive, and should be `ZIP_STORED`, `ZIP_DEFLATED`, `ZIP_BZIP2` or `ZIP_LZMA`; unrecognized values will cause `RuntimeError` to be raised. If `ZIP_DEFLATED`, `ZIP_BZIP2` or `ZIP_LZMA` is specified but the corresponded module (`zlib`, `bz2` or `lzma`) is not available, `RuntimeError` is also raised. The default is `ZIP_STORED`. If allowZip64 is `True` zipfile will create ZIP files that use the ZIP64 extensions when the zipfile is larger than 2 GiB. If it is false (the default) `zipfile` will raise an exception when the ZIP file would require ZIP64 extensions. ZIP64 extensions are disabled by default because the default zip and unzip commands on Unix (the InfoZIP utilities) don’t support these extensions.

  If the file is created with mode `'a'` or `'w'` and then `closed` without adding any files to the archive, the appropriate ZIP structures for an empty archive will be written to the file.

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

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

  New in version 3.2: Added the ability to use `ZipFile` as a context manager.

  Changed in version 3.3: Added support for `bzip2` and `lzma` compression.

`ZipFile.` `close`()

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

`ZipFile.` `getinfo`(name)

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

`ZipFile.` `infolist`()

  Return a list containing a `ZipInfo` object for each member of the archive. The objects are in the same order as their entries in the actual ZIP file 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)

  Extract a member from the archive as a file-like object (ZipExtFile). name is the name of the file in the archive, or a `ZipInfo` object. The mode parameter, if included, must be one of the following: `'r'` (the default), `'U'`, or `'rU'`. Choosing `'U'` or `'rU'` will enable universal newlines support in the read-only object. pwd is the password used for encrypted files. Calling `open()` on a closed ZipFile will raise a `RuntimeError`.

  Note

  The file-like object is read-only and provides the following methods: `read()`, `readline()`, `readlines()`, `__iter__()`, `__next__()`.

  Note

  If the ZipFile was created by passing in a file-like object as the first argument to the constructor, then the object returned by `open()` shares the ZipFile’s file pointer. Under these circumstances, the object returned by `open()` should not be used after any additional operations are performed on the ZipFile object. If the ZipFile was created by passing in a string (the filename) as the first argument to the constructor, then `open()` will create a new file object that will be held by the ZipExtFile, allowing it to operate independently of the ZipFile.

  Note

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

`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 is extracted as accurately as possible. path specifies a different directory to extract to. member can be a filename or a `ZipInfo` object. pwd is the password used for encrypted files.

  Note

  If a member filename is an absolute path, a drive/UNC sharepoint and leading (back)slashes will be stripped, e.g.: `///foo/bar` becomes `foo/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 illegal characters (`:`, `<`, `>`, `|`, `"`, `?`, and `*`) replaced by underscore (`_`).

`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 must be a subset of the list returned by `namelist()`. pwd is the password used for encrypted files.

  Warning

  Never extract archives from untrusted sources without prior inspection. It is possible that files are created outside of path, e.g. members that have absolute filenames starting with `"/"` or filenames with two dots `".."`.

  Changed in version 3.3.1: The zipfile module attempts to prevent that. See `extract()` note.

`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 the file in the archive, or a `ZipInfo` object. The archive must be open for read or append. pwd is the password used for encrypted files and, if specified, it will override the default password set with `setpassword()`. Calling `read()` on a closed ZipFile will raise a `RuntimeError`.

`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`. Calling `testzip()` on a closed ZipFile will raise a `RuntimeError`.

`ZipFile.` `write`(filename, arcname=None, compress_type=None)

  Write the file named filename to the archive, giving it the archive name arcname (by default, this will be the same as filename, but without a drive letter and with leading path separators removed). If given, compress_type overrides the value given for the compression parameter to the constructor for the new entry. The archive must be open with mode `'w'` or `'a'` – calling `write()` on a ZipFile created with mode `'r'` will raise a `RuntimeError`. Calling `write()` on a closed ZipFile will raise a `RuntimeError`.

  Note

  There is no official file name encoding for ZIP files. If you have unicode file names, you must convert them to byte strings in your desired encoding before passing them to `write()`. WinZip interprets all file names as encoded in CP437, also known as DOS Latin.

  Note

  Archive names should be relative to the archive root, that is, they should not start with a path separator.

  Note

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

`ZipFile.` `writestr`(zinfo_or_arcname, bytes[, compress_type])

  Write the string bytes to the archive; zinfo_or_arcname is either the file name it will be given in the archive, or a `ZipInfo` instance. If it’s an instance, at least the filename, date, and time must be given. If it’s a name, the date and time is set to the current date and time. The archive must be opened with mode `'w'` or `'a'` – calling `writestr()` on a ZipFile created with mode `'r'` will raise a `RuntimeError`. Calling `writestr()` on a closed ZipFile will raise a `RuntimeError`.

  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).

  Note

  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, the `ZipInfo` constructor sets this member to `ZIP_STORED`.

  Changed in version 3.2: The compress_type argument.

The following data attributes are also available:

`ZipFile.` `debug`

  The level of debug output to use. This may be set from `0` (the default, no output) to `3` (the most output). Debugging information is written to `sys.stdout`.

`ZipFile.` `comment`

  The comment text associated with the ZIP file. If assigning a comment to a `ZipFile` instance created with mode ‘a’ or ‘w’, this should be a string no longer than 65535 bytes. Comments longer than this will be truncated in the written archive when `close()` is called.

## 13.5.2. PyZipFile Objects

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

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

  New in version 3.2: The optimize parameter.

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

  `writepy`(pathname, basename='')

    Search for files `*.py` and add the corresponding file to the archive.

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

    If the optimize parameter to `PyZipFile` was `0`, `1` or `2`, only files with that optimization level (see `compile()`) are added to the archive, compiling if necessary.

    If the pathname is a file, the filename must end with `.py`, and just the (corresponding `*.py[co]`) file is added at the top level (no path information). If the 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 `*.py[co]` are added at the top level. If the directory is a package directory, then all `*.py[co]` are added under the package name as a file path, and if any subdirectories are package directories, all of these are added recursively. basename is intended for internal use only. The `writepy()` method makes archives with file names like this:

        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

## 13.5.3. ZipInfo Objects

Instances of the `ZipInfo` class are returned by the `getinfo()` and `infolist()` methods of `ZipFile` objects. Each object stores information about a single member of the ZIP archive.

Instances have the following attributes:

`ZipInfo.` `filename`

  Name of the file in the archive.

`ZipInfo.` `date_time`

  The time and date of the last modification to the archive member. This is a tuple of six values:

  Index | Value
  --- | ---
  `0` | Year (>= 1980)
  `1` | Month (one-based)
  `2` | Day of month (one-based)
  `3` | Hours (zero-based)
  `4` | Minutes (zero-based)
  `5` | Seconds (zero-based)

  Note

  The ZIP file format does not support timestamps before 1980.

`ZipInfo.` `compress_type`

  Type of compression for the archive member.

`ZipInfo.` `comment`

  Comment for the individual archive member.

`ZipInfo.` `extra`

  Expansion field data. The PKZIP Application Note contains some comments on the internal structure of the data contained in this string.

`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`

  Must be zero.

`ZipInfo.` `flag_bits`

  ZIP flag bits.

`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.

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