pkgutil

Utilities to support packages.

Classes

ImpImporter

PEP 302 Finder that wraps Python's "classic" import algorithm

    ImpImporter(dirname) produces a PEP 302 finder that searches that
    directory.  ImpImporter(None) produces a PEP 302 finder that searches
    the current sys.path, plus any modules that are frozen or built-in.

    Note that ImpImporter does not currently support being used by placement
    on sys.meta_path.

find_module(self, fullname, path=None)

iter_modules(self, prefix='')

ImpLoader

PEP 302 Loader that wraps Python's "classic" import algorithm

get_code(self, fullname=None)

get_data(self, pathname)

get_filename(self, fullname=None)

get_source(self, fullname=None)

is_package(self, fullname)

load_module(self, fullname)

code = None

source = None

ModuleInfo

A namedtuple with minimal info about a module.

count(self, value, /)

  Return number of occurrences of value.

index(self, value, start=0, stop=9223372036854775807, /)

  Return first index of value.

  Raises ValueError if the value is not present.

ispkg = _tuplegetter(2, 'Alias for field number 2')
  Alias for field number 2

module_finder = _tuplegetter(0, 'Alias for field number 0')
  Alias for field number 0

name = _tuplegetter(1, 'Alias for field number 1')
  Alias for field number 1

module

Create a module object.

The name must be a string; the optional doc argument can have any type.

zipimporter

zipimporter(archivepath) -> zipimporter object

    Create a new zipimporter instance. 'archivepath' must be a path to
    a zipfile, or to a specific path inside a zipfile. For example, it can be
    '/tmp/myimport.zip', or '/tmp/myimport.zip/mydirectory', if mydirectory is a
    valid directory inside the archive.

    'ZipImportError is raised if 'archivepath' doesn't point to a valid Zip
    archive.

    The 'archive' attribute of zipimporter objects contains the name of the
    zipfile targeted.

find_loader(self, fullname, path=None)

  find_loader(fullname, path=None) -> self, str or None.

          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, a string containing the
          full path name if it's possibly a portion of a namespace package,
          or None otherwise. The optional 'path' argument is ignored -- it's
          there for compatibility with the importer protocol.

find_module(self, fullname, path=None)

  find_module(fullname, path=None) -> self or None.

          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(self, fullname)

  get_code(fullname) -> code object.

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

get_data(self, pathname)

  get_data(pathname) -> string with file data.

          Return the data associated with 'pathname'. Raise OSError if
          the file wasn't found.

get_filename(self, fullname)

  get_filename(fullname) -> filename string.

          Return the filename for the specified module.

get_resource_reader(self, fullname)

  Return the ResourceReader for a package in a zip file.

          If 'fullname' is a package within the zip file, return the
          'ResourceReader' object for the package.  Otherwise return None.

get_source(self, fullname)

  get_source(fullname) -> source string.

          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(self, fullname)

  is_package(fullname) -> bool.

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

load_module(self, fullname)

  load_module(fullname) -> module.

          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.

Functions

extend_path

extend_path(path, name)

  Extend a package's path.

      Intended use is to place the following code in a package's __init__.py:

          from pkgutil import extend_path
          __path__ = extend_path(__path__, __name__)

      This will add to the package's __path__ all subdirectories of
      directories on sys.path named after the package.  This is useful
      if one wants to distribute different parts of a single logical
      package as multiple directories.

      It also looks for *.pkg files beginning where * matches the name
      argument.  This feature is similar to *.pth files (see site.py),
      except that it doesn't special-case lines starting with 'import'.
      A *.pkg file is trusted at face value: apart from checking for
      duplicates, all entries found in a *.pkg file are added to the
      path, regardless of whether they are exist the filesystem.  (This
      is a feature.)

      If the input path is not a list (as is the case for frozen
      packages) it is returned unchanged.  The input path is not
      modified; an extended copy is returned.  Items are only appended
      to the copy at the end.

      It is assumed that sys.path is a sequence.  Items of sys.path that
      are not (unicode or 8-bit) strings referring to existing
      directories are ignored.  Unicode items of sys.path that cause
      errors when used as filenames may cause this function to raise an
      exception (in line with os.path.isdir() behavior).

find_loader

find_loader(fullname)

  Find a "loader" object for fullname

      This is a backwards compatibility wrapper around
      importlib.util.find_spec that converts most failures to ImportError
      and only returns the loader rather than the full spec

get_data

get_data(package, resource)

  Get a resource from a package.

      This is a wrapper round the PEP 302 loader get_data API. The package
      argument should be the name of a package, in standard module format
      (foo.bar). The resource argument should be in the form of a relative
      filename, using '/' as the path separator. The parent directory name '..'
      is not allowed, and nor is a rooted name (starting with a '/').

      The function returns a binary string, which is the contents of the
      specified resource.

      For packages located in the filesystem, which have already been imported,
      this is the rough equivalent of

          d = os.path.dirname(sys.modules[package].__file__)
          data = open(os.path.join(d, resource), 'rb').read()

      If the package cannot be located or loaded, or it uses a PEP 302 loader
      which does not support get_data(), then None is returned.

get_importer

get_importer(path_item)

  Retrieve a finder for the given path item

      The returned finder is cached in sys.path_importer_cache
      if it was newly created by a path hook.

      The cache (or part of it) can be cleared manually if a
      rescan of sys.path_hooks is necessary.

get_loader

get_loader(module_or_name)

  Get a "loader" object for module_or_name

      Returns None if the module cannot be found or imported.
      If the named module is not already imported, its containing package
      (if any) is imported, in order to establish the package __path__.

iter_importer_modules

iter_importer_modules(importer, prefix='')

iter_importers

iter_importers(fullname='')

  Yield finders for the given module name

      If fullname contains a '.', the finders will be for the package
      containing fullname, otherwise they will be all registered top level
      finders (i.e. those on both sys.meta_path and sys.path_hooks).

      If the named module is in a package, that package is imported as a side
      effect of invoking this function.

      If no module name is specified, all top level finders are produced.

iter_modules

iter_modules(path=None, prefix='')

  Yields ModuleInfo for all submodules on path,
      or, if path is None, all top-level modules on sys.path.

      'path' should be either None or a list of paths to look for
      modules in.

      'prefix' is a string to output on the front of every module name
      on output.

iter_zipimport_modules

iter_zipimport_modules(importer, prefix='')

namedtuple

namedtuple(typename, field_names, *, rename=False, defaults=None, module=None)

  Returns a new subclass of tuple with named fields.

      >>> Point = namedtuple('Point', ['x', 'y'])
      >>> Point.__doc__                   # docstring for the new class
      'Point(x, y)'
      >>> p = Point(11, y=22)             # instantiate with positional args or keywords
      >>> p[0] + p[1]                     # indexable like a plain tuple
      33
      >>> x, y = p                        # unpack like a regular tuple
      >>> x, y
      (11, 22)
      >>> p.x + p.y                       # fields also accessible by name
      33
      >>> d = p._asdict()                 # convert to a dictionary
      >>> d['x']
      11
      >>> Point(**d)                      # convert from a dictionary
      Point(x=11, y=22)
      >>> p._replace(x=100)               # _replace() is like str.replace() but targets named fields
      Point(x=100, y=22)

read_code

read_code(stream)

resolve_name

resolve_name(name)


      Resolve a name to an object.

      It is expected that `name` will be a string in one of the following
      formats, where W is shorthand for a valid Python identifier and dot stands
      for a literal period in these pseudo-regexes:

      W(.W)*
      W(.W)*:(W(.W)*)?

      The first form is intended for backward compatibility only. It assumes that
      some part of the dotted name is a package, and the rest is an object
      somewhere within that package, possibly nested inside other objects.
      Because the place where the package stops and the object hierarchy starts
      can't be inferred by inspection, repeated attempts to import must be done
      with this form.

      In the second form, the caller makes the division point clear through the
      provision of a single colon: the dotted name to the left of the colon is a
      package to be imported, and the dotted name to the right is the object
      hierarchy within that package. Only one import is needed in this form. If
      it ends with the colon, then a module object is returned.

      The function will return an object (which might be a module), or raise one
      of the following exceptions:

      ValueError - if `name` isn't in a recognised format
      ImportError - if an import failed when it shouldn't have
      AttributeError - if a failure occurred when traversing the object hierarchy
                       within the imported package to get to the desired object.

simplegeneric

singledispatch(func)

  Single-dispatch generic function decorator.

      Transforms a function into a generic function, which can have different
      behaviours depending upon the type of its first argument. The decorated
      function acts as the default implementation, and additional
      implementations can be registered using the register() attribute of the
      generic function.

walk_packages

walk_packages(path=None, prefix='', onerror=None)

  Yields ModuleInfo for all modules recursively
      on path, or, if path is None, all accessible modules.

      'path' should be either None or a list of paths to look for
      modules in.

      'prefix' is a string to output on the front of every module name
      on output.

      Note that this function must import all *packages* (NOT all
      modules!) on the given path, in order to access the __path__
      attribute to find submodules.

      'onerror' is a function which gets called with one argument (the
      name of the package which was being imported) if any exception
      occurs while trying to import a package.  If no onerror function is
      supplied, ImportErrors are caught and ignored, while all other
      exceptions are propagated, terminating the search.

      Examples:

      # list all modules python can access
      walk_packages()

      # list all submodules of ctypes
      walk_packages(ctypes.__path__, ctypes.__name__+'.')

Modules