sympy/thirdparty/__init__.py

   1 """Thirdparty Packages for internal use.
   2 """
   3
   4 import sys
   5 import os
   6
   7 def import_thirdparty(lib):
   8     """
   9     Imports a thirdparty package "lib" by setting all paths correctly.
  10
  11     At the moment, there is only the "pyglet" library, so we just put
  12     pyglet to sys.path temporarily, then import "lib" and then restore the path.
  13     With more packages, we'll just put them to sys.path as well.
  14     """
  15
  16     seen = set()
  17     def new_import(name, globals={}, locals={}, fromlist=[]):
  18         if name in seen:
  19             return old_import(name, globals, locals, fromlist)
  20         seen.add(name)
  21         sys.path.insert(0, os.path.join(os.path.abspath(os.path.dirname( \
  22             __file__)), "pyglet"))
  23         try:
  24             m = old_import(name, globals, locals, fromlist)
  25         finally:
  26             del sys.path[0]
  27         return m
  28     import __builtin__
  29     old_import = __builtin__.__import__
  30     __builtin__.__import__ = new_import
  31     try:
  32         m = __import__(lib)
  33     finally:
  34         __builtin__.__import__ = old_import
  35
  36     return m