Windows上的Matplotlib - 依赖性尚未解决

Question

我在Windows更新后使用matplotlib时遇到问题。我正在运行Windows 7 Service Pack 1 32位，我安装了Python和matplotlib作为Python（x，y）-2.7.6.1的一部分。问题似乎与FreeType有关，因为导入在ft2font上失败，如下面的堆栈跟踪所示：

In [1]: import matplotlib

In [2]: matplotlib.use('agg')

In [3]: import matplotlib.pyplot as plt
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-3-eff513f636fd> in <module>()
----> 1 import matplotlib.pyplot as plt

C:\Python27\lib\site-packages\matplotlib\pyplot.py in <module>()
     22
     23 import matplotlib
---> 24 import matplotlib.colorbar
     25 from matplotlib import _pylab_helpers, interactive
     26 from matplotlib.cbook import dedent, silent_list, is_string_like, is_numlike

C:\Python27\lib\site-packages\matplotlib\colorbar.py in <module>()
     27 import matplotlib.artist as martist
     28 import matplotlib.cbook as cbook
---> 29 import matplotlib.collections as collections
     30 import matplotlib.colors as colors
     31 import matplotlib.contour as contour

C:\Python27\lib\site-packages\matplotlib\collections.py in <module>()
     21 import matplotlib.artist as artist
     22 from matplotlib.artist import allow_rasterization
---> 23 import matplotlib.backend_bases as backend_bases
     24 import matplotlib.path as mpath
     25 from matplotlib import _path

C:\Python27\lib\site-packages\matplotlib\backend_bases.py in <module>()
     48
     49 import matplotlib.tight_bbox as tight_bbox
---> 50 import matplotlib.textpath as textpath
     51 from matplotlib.path import Path
     52 from matplotlib.cbook import mplDeprecation

C:\Python27\lib\site-packages\matplotlib\textpath.py in <module>()
      9 from matplotlib.path import Path
     10 from matplotlib import rcParams
---> 11 import matplotlib.font_manager as font_manager
     12 from matplotlib.ft2font import FT2Font, KERNING_DEFAULT, LOAD_NO_HINTING
     13 from matplotlib.ft2font import LOAD_TARGET_LIGHT

C:\Python27\lib\site-packages\matplotlib\font_manager.py in <module>()
     51 import matplotlib
     52 from matplotlib import afm
---> 53 from matplotlib import ft2font
     54 from matplotlib import rcParams, get_cachedir
     55 from matplotlib.cbook import is_string_like

ImportError: DLL load failed: The specified procedure could not be found.

我尝试重新安装Python（x，y），但这并没有解决问题。

从Stackoverflow上的其他答案我了解到，此处的常见故障包括缺少msvcr90.dll和msvcp90.dll个文件。我下载了Dependency Walker并打开了c:\Python27\Lib\site-packages\matplotlib\FT2FONT.PYD。这显示了这些文件和libbz2.dll的问题。我下载并将这些文件复制到c:\windows\system32。

我也尝试检查我的PATH和PYTHONPATH环境变量，但它们似乎正确引用了我的Python安装：

PATH: C:\Python27\Lib\site-packages\PyQt4;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Novell\GroupWise;C:\Program Files\MiKTeX 2.9\miktex\bin\;C:\Program Files\Microsoft SQL Server\80\Tools\Binn\;C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;C:\Program Files\Common Files\AspenTech Shared\;C:\Python27;C:\Python27\DLLs;C:\Python27\Scripts;C:\Python27\gnuplot\binary;C:\Program Files\pythonxy\SciTE-3.3.2-3;C:\Program Files\pythonxy\console;C:\MinGW32-xy\bin;C:\Python27\Lib\site-packages\vtk
PYTHONPATH: c:\Python27\DLLs

即使只使用上面会话中显示的Agg后端，问题也会出现，所以我不认为它与Qt或tk有任何关系。

Answer 1

问题似乎是由应用程序在C:\Windows\System32\libbz2.dll中安装不同/不兼容的BZ2版本引起的。这被用来代替Python（x，y）安装的Python27目录中的同名DLL。这就是Dependency Walker中出现的情况：

您可以看到libbz2.dll出现问题，即使Dependency Walker没有将其列为依赖性错误。重命名或删除C:\Windows\System32\中的版本会导致依赖关系由c:\Python27\DLLs中的版本解析。