importlib.util

Utility code for constructing importers, etc.

Classes

LazyLoader

A loader that creates a module which defers loading until attribute access.

create_module(self, spec)

exec_module(self, module)

  Make the module load lazily.

factory(loader)

  Construct a callable which returns the eager loader made lazy.

load_module(self, fullname)

  Return the loaded module.

          The module must be added to sys.modules and have import-related
          attributes set properly.  The fullname is a str.

          ImportError is raised on failure.

          This method is deprecated in favor of loader.exec_module(). If
          exec_module() exists then it is used to provide a backwards-compatible
          functionality for this method.

module_repr(self, module)

  Return a module's repr.

          Used by the module type when the method does not raise
          NotImplementedError.

          This method is deprecated.

Loader

Abstract base class for import loaders.

create_module(self, spec)

  Return a module to initialize and into which to load.

          This method should raise ImportError if anything prevents it
          from creating a new module.  It may return None to indicate
          that the spec should create the new module.

load_module(self, fullname)

  Return the loaded module.

          The module must be added to sys.modules and have import-related
          attributes set properly.  The fullname is a str.

          ImportError is raised on failure.

          This method is deprecated in favor of loader.exec_module(). If
          exec_module() exists then it is used to provide a backwards-compatible
          functionality for this method.

module_repr(self, module)

  Return a module's repr.

          Used by the module type when the method does not raise
          NotImplementedError.

          This method is deprecated.

Functions

cache_from_source

cache_from_source(path, debug_override=None, *, optimization=None)

  Given the path to a .py file, return the path to its .pyc file.

      The .py file does not need to exist; this simply returns the path to the
      .pyc file calculated as if the .py file were imported.

      The 'optimization' parameter controls the presumed optimization level of
      the bytecode file. If 'optimization' is not None, the string representation
      of the argument is taken and verified to be alphanumeric (else ValueError
      is raised).

      The debug_override parameter is deprecated. If debug_override is not None,
      a True value is the same as setting 'optimization' to the empty string
      while a False value is equivalent to setting 'optimization' to '1'.

      If sys.implementation.cache_tag is None then NotImplementedError is raised.

contextmanager

contextmanager(func)

  @contextmanager decorator.

      Typical usage:

          @contextmanager
          def some_generator(<arguments>):
              <setup>
              try:
                  yield <value>
              finally:
                  <cleanup>

      This makes this:

          with some_generator(<arguments>) as <variable>:
              <body>

      equivalent to this:

          <setup>
          try:
              <variable> = <value>
              <body>
          finally:
              <cleanup>

decode_source

decode_source(source_bytes)

  Decode bytes representing source code and return the string.

      Universal newline support is used in the decoding.

find_spec

find_spec(name, package=None)

  Return the spec for the specified module.

      First, sys.modules is checked to see if the module was already imported. If
      so, then sys.modules[name].__spec__ is returned. If that happens to be
      set to None, then ValueError is raised. If the module is not in
      sys.modules, then sys.meta_path is searched for a suitable spec with the
      value of 'path' given to the finders. None is returned if no spec could
      be found.

      If the name is for submodule (contains a dot), the parent module is
      automatically imported.

      The name and package arguments work the same as importlib.import_module().
      In other words, relative module names (with leading dots) work.

module_for_loader

module_for_loader(fxn)

  Decorator to handle selecting the proper module for loaders.

      The decorated function is passed the module to use instead of the module
      name. The module passed in to the function is either from sys.modules if
      it already exists or is a new module. If the module is new, then __name__
      is set the first argument to the method, __loader__ is set to self, and
      __package__ is set accordingly (if self.is_package() is defined) will be set
      before it is passed to the decorated function (if self.is_package() does
      not work for the module it will be set post-load).

      If an exception is raised and the decorator created the module it is
      subsequently removed from sys.modules.

      The decorator assumes that the decorated function takes the module name as
      the second argument.

module_from_spec

module_from_spec(spec)

  Create a module based on the provided spec.

resolve_name

resolve_name(name, package)

  Resolve a relative module name to an absolute one.

set_loader

set_loader(fxn)

  Set __loader__ on the returned module.

      This function is deprecated.

set_package

set_package(fxn)

  Set __package__ on the returned module.

      This function is deprecated.

source_from_cache

source_from_cache(path)

  Given the path to a .pyc. file, return the path to its .py file.

      The .pyc file does not need to exist; this simply returns the path to
      the .py file calculated to correspond to the .pyc file.  If path does
      not conform to PEP 3147/488 format, ValueError will be raised. If
      sys.implementation.cache_tag is None then NotImplementedError is raised.

source_hash

source_hash(source_bytes)

  Return the hash of *source_bytes* as used in hash-based pyc files.

spec_from_file_location

spec_from_file_location(name, location=None, *, loader=None, submodule_search_locations=<object object at 0x7f75e3c940d0>)

  Return a module spec based on a file location.

      To indicate that the module is a package, set
      submodule_search_locations to a list of directory paths.  An
      empty list is sufficient, though its not otherwise useful to the
      import system.

      The loader must take a spec as its only __init__() arg.

spec_from_loader

spec_from_loader(name, loader, *, origin=None, is_package=None)

  Return a module spec based on various loader methods.

Other members

MAGIC_NUMBER = b'o\r\r\n'

Modules