importerror dll加载失败导入mpl_toolkits.basemap时无法找到指定的模块

Question

Traceback (most recent call last):
  File "<pyshell#5>", line 1, in <module>
    import mpl_toolkits.basemap
  File "C:\Python27\lib\site-packages\mpl_toolkits\basemap\__init__.py", line 26, in <module>
    from matplotlib.collections import LineCollection
  File "C:\Python27\lib\site-packages\matplotlib\collections.py", line 23, in <module>
    import matplotlib.backend_bases as backend_bases
  File "C:\Python27\lib\site-packages\matplotlib\backend_bases.py", line 50, in <module>
    import matplotlib.textpath as textpath
  File "C:\Python27\lib\site-packages\matplotlib\textpath.py", line 11, in <module>
    import matplotlib.font_manager as font_manager
  File "C:\Python27\lib\site-packages\matplotlib\font_manager.py", line 53, in <module>
    from matplotlib import ft2font
ImportError: DLL load failed: The specified module could not be found.

为什么我会收到此异常？