zipimport — Load Python Code from ZIP Archives¶

Example¶

These examples reuse some of the code from the discussion of zipfile to create an example ZIP archive containing a few Python modules.

import sys
import zipfile

if __name__ == '__main__':
    zf = zipfile.PyZipFile('zipimport_example.zip', mode='w')
    try:
        zf.writepy('.')
        zf.write('zipimport_get_source.py')
        zf.write('example_package/README.txt')
    finally:
        zf.close()
    for name in zf.namelist():
        print(name)

Run zipimport_make_example.py before any of the rest of the examples to create a ZIP archive containing all of the modules in the example directory, along with some test data needed for the examples in this section.

$ python3 zipimport_make_example.py

__init__.pyc
example_package/__init__.pyc
zipimport_find_module.pyc
zipimport_get_code.pyc
zipimport_get_data.pyc
zipimport_get_data_nozip.pyc
zipimport_get_data_zip.pyc
zipimport_get_source.pyc
zipimport_is_package.pyc
zipimport_load_module.pyc
zipimport_make_example.pyc
zipimport_get_source.py
example_package/README.txt

Finding a Module¶

Given the full name of a module, find_module() will try to locate that module inside the ZIP archive.

import zipimport

importer = zipimport.zipimporter('zipimport_example.zip')

for module_name in ['zipimport_find_module', 'not_there']:
    print(module_name, ':', importer.find_module(module_name))

If the module is found, the zipimporter instance is returned. Otherwise, None is returned.

$ python3 zipimport_find_module.py

zipimport_find_module : <zipimporter object
"zipimport_example.zip">
not_there : None

Accessing Code¶

The get_code() method loads the code object for a module from the archive.

import zipimport

importer = zipimport.zipimporter('zipimport_example.zip')
code = importer.get_code('zipimport_get_code')
print(code)

The code object is not the same as a module object, but is used to create one.

$ python3 zipimport_get_code.py

<code object <module> at 0x1012b4ae0, file
"./zipimport_get_code.py", line 6>

To load the code as a usable module, use load_module() instead.

import zipimport

importer = zipimport.zipimporter('zipimport_example.zip')
module = importer.load_module('zipimport_get_code')
print('Name   :', module.__name__)
print('Loader :', module.__loader__)
print('Code   :', module.code)

The result is a module object configured as though the code had been loaded from a regular import.

$ python3 zipimport_load_module.py

<code object <module> at 0x1007b4c00, file
"./zipimport_get_code.py", line 6>
Name   : zipimport_get_code
Loader : <zipimporter object "zipimport_example.zip">
Code   : <code object <module> at 0x1007b4c00, file
"./zipimport_get_code.py", line 6>

Source¶

As with the inspect module, it is possible to retrieve the source code for a module from the ZIP archive, if the archive includes the source. In the case of the example, only zipimport_get_source.py is added to zipimport_example.zip (the rest of the modules are just added as the .pyc files).

import zipimport

modules = [
    'zipimport_get_code',
    'zipimport_get_source',
]

importer = zipimport.zipimporter('zipimport_example.zip')
for module_name in modules:
    source = importer.get_source(module_name)
    print('=' * 80)
    print(module_name)
    print('=' * 80)
    print(source)
    print()

If the source for a module is not available, get_source() returns None.

$ python3 zipimport_get_source.py

================================================================
zipimport_get_code
================================================================
None

================================================================
zipimport_get_source
================================================================
#!/usr/bin/env python3
#
# Copyright 2007 Doug Hellmann.
#
"""Retrieving the source code for a module within a zip archive.
"""

#end_pymotw_header
import zipimport

modules = [
    'zipimport_get_code',
    'zipimport_get_source',
]

importer = zipimport.zipimporter('zipimport_example.zip')
for module_name in modules:
    source = importer.get_source(module_name)
    print('=' * 80)
    print(module_name)
    print('=' * 80)
    print(source)
    print()

Packages¶

To determine if a name refers to a package instead of a regular module, use is_package().

import zipimport

importer = zipimport.zipimporter('zipimport_example.zip')
for name in ['zipimport_is_package', 'example_package']:
    print(name, importer.is_package(name))

In this case, zipimport_is_package came from a module and the example_package is a package.

$ python3 zipimport_is_package.py

zipimport_is_package False
example_package True

Data¶

There are times when source modules or packages need to be distributed with non-code data. Images, configuration files, default data, and test fixtures are just a few examples of this. Frequently, the module __path__ or __file__ attributes are used to find these data files relative to where the code is installed.

For example, with a “normal” module, the file system path can be constructed from the __file__ attribute of the imported package like this:

import os
import example_package

# Find the directory containing the imported
# package and build the data filename from it.
pkg_dir = os.path.dirname(example_package.__file__)
data_filename = os.path.join(pkg_dir, 'README.txt')

# Read the file and show its contents.
print(data_filename, ':')
print(open(data_filename, 'r').read())

The output will depend on where the sample code is located on the file system.

$ python3 zipimport_get_data_nozip.py

.../example_package/README.txt :
This file represents sample data which could be embedded in the
ZIP archive.  You could include a configuration file, images, or
any other sort of noncode data.

If the example_package is imported from the ZIP archive instead of the file system, using __file__ does not work.

import sys
sys.path.insert(0, 'zipimport_example.zip')

import os
import example_package
print(example_package.__file__)
data_filename = os.path.join(
    os.path.dirname(example_package.__file__),
    'README.txt',
)
print(data_filename, ':')
print(open(data_filename, 'rt').read())

The __file__ of the package refers to the ZIP archive, and not a directory, so building up the path to the README.txt file gives the wrong value.

$ python3 zipimport_get_data_zip.py

zipimport_example.zip/example_package/__init__.pyc
zipimport_example.zip/example_package/README.txt :
Traceback (most recent call last):
  File "zipimport_get_data_zip.py", line 20, in <module>
    print(open(data_filename, 'rt').read())
NotADirectoryError: [Errno 20] Not a directory:
'zipimport_example.zip/example_package/README.txt'

A more reliable way to retrieve the file is to use the get_data() method. The zipimporter instance that loaded the module can be accessed through the __loader__ attribute of the imported module:

import sys
sys.path.insert(0, 'zipimport_example.zip')

import os
import example_package
print(example_package.__file__)
data = example_package.__loader__.get_data(
    'example_package/README.txt')
print(data.decode('utf-8'))

pkgutil.get_data() uses this interface to access data from within a package. The value returned is a byte string, which needs to be decoded to a unicode string before printing.

$ python3 zipimport_get_data.py

zipimport_example.zip/example_package/__init__.pyc
This file represents sample data which could be embedded in the
ZIP archive.  You could include a configuration file, images, or
any other sort of noncode data.

The __loader__ is not set for modules not imported via zipimport.