windows下安装pygraphviz过程 及 相关错误解决

简单的在windows安装pygraphiviz的过程如下：

1. 首先安装graphviz,  http://www.graphviz.org/pub/graphviz/stable/windows/graphviz-2.28.0.msi

2. 下载pygraphviz源码包， http://pypi.python.org/packages/source/p/pygraphviz/pygraphviz-1.1.zip

3. 解压后
    1. 修改setup.py，三个地方要改
        library_path=r'D:\Program Files (x86)\Graphviz 2.28\lib\release\lib'   #按你的graphviz路径修改
        include_path=r'D:\Program Files (x86)\Graphviz 2.28\include\graphviz'   #按你的graphviz路径修改
    2. 修改文件unixcompiler.py，一般是285行（“C:\python27\lib\distutils\unixcompiler.py"）如下：
        old:  compiler = os.path.basename(sysconfig.get_config_var("CC"))
        new: compiler =  "gcc"
        编译完pygraphviz后，记得改回去。

4. python setup.py build -c mingw32   要先确定已安装mingw32
5. 手工拷贝pygraphviz目录（像：D:\Downloads\pygraphviz\build\lib.win32-2.7） 到python的site-packages下：C:\Python27\Lib\site-packages
6. 检查下是否安装成功
    import pygraphviz

按上述方法基本就可以安装成功。

但是，我在这个过程中碰见如下几个问题：
1. 尝试用python setup.py build -c mingw32的时候，碰到：gcc: 错误：unrecognized command line option ‘-mno-cygwin’
错误如下：
     running build_ext
     building 'pygraphviz._graphviz' extension
     d:\MinGW\bin\gcc.exe -mno-cygwin -mdll -O -Wall "-ID:\Program Files (x86)\Graphviz 2.28\include\grap
     hviz" -ID:\Python\Python27\include -ID:\Python\Python27\PC -c pygraphviz/graphviz_wrap.c -o build\te
     mp.win32-2.7\Release\pygraphviz\graphviz_wrap.o
     gcc: 错误：unrecognized command line option ‘-mno-cygwin’
     error: command 'gcc' failed with exit status 1
原因：
    mingw版本太新了...无语...找了个老版本的mingw32就可以了。

2. 编译过程中，碰见：cannot find -lcgraph
错误如下：
    D:\Downloads\pygraphviz>python setup.py build -c mingw32
     elease\libth=D:\Program Files (x86)\Graphviz 2.28\lib
     include_path=D:\Program Files (x86)\Graphviz 2.28\include\graphviz
     running build
     running build_py
     running build_ext
     building 'pygraphviz._graphviz' extension
     C:\MinGW\bin\gcc.exe -mno-cygwin -mdll -O -Wall "-ID:\Program Files (x86)\Graphviz 2.28\include\grap
     hviz" -ID:\Python\Python27\include -ID:\Python\Python27\PC -c pygraphviz/graphviz_wrap.c -o build\te
     mp.win32-2.7\Release\pygraphviz\graphviz_wrap.o
     pygraphviz/graphviz_wrap.c: In function 'agattr_label':
     pygraphviz/graphviz_wrap.c:2855: warning: return makes integer from pointer without a cast
     writing build\temp.win32-2.7\Release\pygraphviz\_graphviz.def
     C:\MinGW\bin\gcc.exe -mno-cygwin -shared -s build\temp.win32-2.7\Release\pygraphviz\graphviz_wrap.o
     elease\lib" -LD:\Python\Python27\libs -LD:\Python\Python27\PCbuild "-Wl,-RD:\Program Files (x86)\Gra
     elease\lib" -lcgraph -lcdt -lpython27 -lmsvcr90 -o build\lib.win32-2.7\pygraphviz\_graphviz.pyd
     c:/mingw/bin/../lib/gcc/mingw32/4.4.1/http://www.cnblogs.com/http://www.cnblogs.com/mingw32/bin/ld.exe: cannot find -lcgraph
     collect2: ld returned 1 exit status
     error: command 'gcc' failed with exit status 1
原因：
    library_path没有设置对。这个要说起windows路径的问题。如果我们把一个路径赋值给一个字符串的时候，简单说有两种
办法保持路径不会被转义或者截断：
    1. 使用原始字符串r：
          library_path=r'D:\Program Files (x86)\Graphviz 2.28\lib\release\lib'
          include_path=r'D:\Program Files (x86)\Graphviz 2.28\include\graphviz'
     2. 自己把'\'改为'\\':
          library_path='D:\\Program Files (x86)\\Graphviz 2.28\\lib\\release\\lib'
          include_path='D:\\Program Files (x86)\\Graphviz 2.28\\include\\graphviz'

3. 测试是否安装成功的时候，发现：ImportError: No module named _graphviz
错误如下：
     D:\Downloads\pygraphviz>python
     Python 2.7 (r27:82525, Jul  4 2010, 09:01:59) [MSC v.1500 32 bit (Intel)] on win32
     Type "help", "copyright", "credits" or "license" for more information.
     >>> import pygraphviz
     Traceback (most recent call last):
       File "", line 1, in
       File "pygraphviz\__init__.py", line 54, in
          from agraph import AGraph, Node, Edge, Attribute, ItemAttribute
       File "pygraphviz\agraph.py", line 19, in
          import graphviz as gv
       File "pygraphviz\graphviz.py", line 7, in
          import _graphviz
     ImportError: No module named _graphviz
原因：
    不要运行python命令在pygraphviz目录下，随便新开个cmd窗口，再次运行python命令并且尝试import，这下就可以了。

转载于:https://www.cnblogs.com/lypkiller/archive/2013/01/07/2849486.html