31.4. "zipimport" — Import modules from Zip archives
****************************************************

New in version 2.3.

This module adds the ability to import Python modules ("*.py",
"*.py[co]") and packages from ZIP-format archives. It is usually not
needed to use the "zipimport" module explicitly; it is automatically
used by the built-in "import" mechanism for "sys.path" items that are
paths to ZIP archives.

Typically, "sys.path" is a list of directory names as strings.  This
module also allows an item of "sys.path" to be a string naming a ZIP
file archive. The ZIP archive can contain a subdirectory structure to
support package imports, and a path within the archive can be
specified to only import from a subdirectory.  For example, the path
"example.zip/lib/" would only import from the "lib/" subdirectory
within the archive.

Any files may be present in the ZIP archive, but only files ".py" and
".py[co]" are available for import.  ZIP import of dynamic modules
(".pyd", ".so") is disallowed. Note that if an archive only contains
".py" files, Python will not attempt to modify the archive by adding
the corresponding ".pyc" or ".pyo" file, meaning that if a ZIP archive
doesn’t contain ".pyc" files, importing may be rather slow.

Using the built-in "reload()" function will fail if called on a module
loaded from a ZIP archive; it is unlikely that "reload()" would be
needed, since this would imply that the ZIP has been altered during
runtime.

ZIP archives with an archive comment are currently not supported.

See also:

  PKZIP Application Note
     Documentation on the ZIP file format by Phil Katz, the creator of
     the format and algorithms used.

  **PEP 273** - Import Modules from Zip Archives
     Written by James C. Ahlstrom, who also provided an
     implementation. Python 2.3 follows the specification in PEP 273,
     but uses an implementation written by Just van Rossum that uses
     the import hooks described in PEP 302.

  **PEP 302** - New Import Hooks
     The PEP to add the import hooks that help this module work.

This module defines an exception:

exception zipimport.ZipImportError

   Exception raised by zipimporter objects. It’s a subclass of
   "ImportError", so it can be caught as "ImportError", too.


31.4.1. zipimporter Objects
===========================

"zipimporter" is the class for importing ZIP files.

class zipimport.zipimporter(archivepath)

   Create a new zipimporter instance. *archivepath* must be a path to
   a ZIP file, or to a specific path within a ZIP file.  For example,
   an *archivepath* of "foo/bar.zip/lib" will look for modules in the
   "lib" directory inside the ZIP file "foo/bar.zip" (provided that it
   exists).

   "ZipImportError" is raised if *archivepath* doesn’t point to a
   valid ZIP archive.

   find_module(fullname[, path])

      Search for a module specified by *fullname*. *fullname* must be
      the fully qualified (dotted) module name. It returns the
      zipimporter instance itself if the module was found, or "None"
      if it wasn’t. The optional *path* argument is ignored—it’s there
      for compatibility with the importer protocol.

   get_code(fullname)

      Return the code object for the specified module. Raise
      "ZipImportError" if the module couldn’t be found.

   get_data(pathname)

      Return the data associated with *pathname*. Raise "IOError" if
      the file wasn’t found.

   get_filename(fullname)

      Return the value "__file__" would be set to if the specified
      module was imported. Raise "ZipImportError" if the module
      couldn’t be found.

   New in version 2.7.

   get_source(fullname)

      Return the source code for the specified module. Raise
      "ZipImportError" if the module couldn’t be found, return "None"
      if the archive does contain the module, but has no source for
      it.

   is_package(fullname)

      Return "True" if the module specified by *fullname* is a
      package. Raise "ZipImportError" if the module couldn’t be found.

   load_module(fullname)

      Load the module specified by *fullname*. *fullname* must be the
      fully qualified (dotted) module name. It returns the imported
      module, or raises "ZipImportError" if it wasn’t found.

   archive

      The file name of the importer’s associated ZIP file, without a
      possible subpath.

   prefix

      The subpath within the ZIP file where modules are searched.
      This is the empty string for zipimporter objects which point to
      the root of the ZIP file.

   The "archive" and "prefix" attributes, when combined with a slash,
   equal the original *archivepath* argument given to the
   "zipimporter" constructor.


31.4.2. Examples
================

Here is an example that imports a module from a ZIP archive - note
that the "zipimport" module is not explicitly used.

   $ unzip -l example.zip
   Archive:  example.zip
     Length     Date   Time    Name
    --------    ----   ----    ----
        8467  11-26-02 22:30   jwzthreading.py
    --------                   -------
        8467                   1 file
   $ ./python
   Python 2.3 (#1, Aug 1 2003, 19:54:32)
   >>> import sys
   >>> sys.path.insert(0, 'example.zip')  # Add .zip file to front of path
   >>> import jwzthreading
   >>> jwzthreading.__file__
   'example.zip/jwzthreading.py'
