12.4. zipfile — Work with ZIP archives

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 GByte 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.

For other archive formats, see the bz2, gzip, and tarfile modules.

The module defines the following items:

exception zipfile.BadZipfile
The error raised for bad ZIP files (old name: zipfile.error).
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.

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.

The numeric constant for an uncompressed archive member.
The numeric constant for the usual ZIP compression method. This requires the zlib module. No other compression methods are currently supported.

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.

12.4.1. 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. Using

cat myzip.zip >> python.exe

also works, and at least WinZip can read such files. 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 or ZIP_DEFLATED; unrecognized values will cause RuntimeError to be raised. If ZIP_DEFLATED is specified but the zlib module 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 GB. 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 close()d without adding any files to the archive, the appropriate ZIP structures for an empty archive will be written to the file.

Close the archive file. You must call close() before exiting your program or essential records will not be written.
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.
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.
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 newline support in the read-only object. pwd is the password used for encrypted files. Calling open() on a closed ZipFile will raise a RuntimeError.


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


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.


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.
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.


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 "..".

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


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.


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


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)

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.


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.

The following data attributes are also available:

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.
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 ZipFile.close() is called.

12.4.2. PyZipFile Objects

The PyZipFile constructor takes the same parameters as the ZipFile constructor. Instances have one method in addition to those of ZipFile objects.

PyZipFile.writepy(pathname, basename='')

Search for files *.py and add the corresponding file to the archive. The corresponding file is a *.pyo file if available, else a *.pyc file, 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

12.4.3. 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:

Name of the file in the archive.

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

Index Value
0 Year
1 Month (one-based)
2 Day of month (one-based)
3 Hours (zero-based)
4 Minutes (zero-based)
5 Seconds (zero-based)
Type of compression for the archive member.
Comment for the individual archive member.
Expansion field data. The PKZIP Application Note contains some comments on the internal structure of the data contained in this string.
System which created ZIP archive.
PKZIP version which created ZIP archive.
PKZIP version needed to extract archive.
Must be zero.
ZIP flag bits.
Volume number of file header.
Internal attributes.
External file attributes.
Byte offset to the file header.
CRC-32 of the uncompressed file.
Size of the compressed data.
Size of the uncompressed file.