demandimport

Delays loading of modules until they are actually used. Perfect for Python apps that need to be snappy like command-line utils. Source-code derived from mercurial.

To enable, write

.. code:: python

import demandimport; demandimport.enable()

Imports of the following form will be delayed

.. code:: python

import a, b.c import a.b as c from a import b, c # a will be loaded immediately, though

These imports with not be delayed

.. code:: python

from a import * b = import(a)

Delayed loading will confuse some third-party modules. In that case you can disable the delay for just that module. For example

.. code:: python

demandimport.ignore('Crypto.PublicKey._fastmath')

There are also versions that can be used with with

.. code:: python

with demandimport.enabled():

do something

  with demandimport.disabled():
     import troublesome.module
  with demandimport.ignored('test'):
     import other.troublemaker

Installation

To install demandimport, simply run::

pip install demandimport

Attribution

Olivia Mackall olivia@selenic.com is the original author of the module in Mercurial on which this module is based. Bas Westerbaan bas@westerbaan.name maintains it now.