Installing PyGraphviz on Windows


Django Extensions provides a bunch of management commands for the Django Framework. One of the most handy is the graph_models command. This command creates a visual representation of the Django models existing in the database.

In order to use this command you need to have Graphviz and PyGraphviz installed on your machine. Graphviz is a package of open-source tools for representing structural information as diagrams of abstract graphs and networks. PyGraphviz is a Python interface for Graphviz and allows you can create, edit, read, write, and draw Graphviz graphs.

Download and install Graphviz from this link:

I couldn’t install PyGraphviz using easy_install, because it depends on Graphviz, and easy_install doesn’t know where to find Graphviz.

Download PyGraphviz(1.1) from this link:, and extract it.

Adjust “” file to reflect your Graphviz instalation.

library_path='C:/Program Files (x86)/Graphviz 2.28/lib/release/lib'
include_path='C:/Program Files (x86)/Graphviz 2.28/include/graphviz'

Normally, you would run python install to build and install a python application, but in this case we need to do some extra work. Running this command will output an error:

"Unable to find vcvarsall.bat"

To solve this issue, PyGraphviz needs to be compiled with a MSVC or mingw32 compiler. I haven’t found a Windows build for PyGraphviz so the only option was to built this myself.

I have used an older release of mingw because the current one doesn’t support the mno-cygwin argument anymore.

Download and install mingw-get-inst-20100831.exe from this link:

Add mingw/bin directory to the system path.

Change line 285 from “c:\python27\lib\distutils\” from

compiler = os.path.basename(sysconfig.get_config_var("CC"))


compiler = "gcc".

or there will be an error “TypeError: ‘NoneType’ object is unsubscriptable”. Change it back after finishing installing PyGraphviz.

Now it’s time to build PyGraphviz:

C:\pygraphviz-1.1>python build -c mingw32
running build
running build_py
creating build
creating build\lib.win32-2.7
creating build\lib.win32-2.7\pygraphviz
copying pygraphviz\ -> build\lib.win32-2.7\pygraphviz
copying pygraphviz\ -> build\lib.win32-2.7\pygraphviz
copying pygraphviz\ -> build\lib.win32-2.7\pygraphviz
copying pygraphviz\ -> build\lib.win32-2.7\pygraphviz
copying pygraphviz\ -> build\lib.win32-2.7\pygraphviz
creating build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\ -> build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\ -> build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\attributes.txt -> build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\graph.txt -> build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\layout_draw.txt -> build\lib.win32-2.7\pygraphviz\tests
copying pygraphviz\tests\unicode.txt -> build\lib.win32-2.7\pygraphviz\tests
running build_ext
building 'pygraphviz._graphviz' extension
creating build\temp.win32-2.7
creating build\temp.win32-2.7\Release
creating build\temp.win32-2.7\Release\pygraphviz
C:\MinGW\bin\gcc.exe -mno-cygwin -mdll -O -Wall -IC:/Graphviz/include/graphviz -
IC:\Python27\include -IC:\Python27\PC -c pygraphviz/graphviz_wrap.c -o build\tem
pygraphviz/graphviz_wrap.c: In function 'agattr_label':
pygraphviz/graphviz_wrap.c:2855:5: warning: return makes integer from pointer wi
thout 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\pygraph
viz\graphviz_wrap.o build\temp.win32-2.7\Release\pygraphviz\_graphviz.def -LC:/G
raphviz/lib/release/lib -LC:\Python27\libs -LC:\Python27\PCbuild -Wl,-RC:/Graphv
iz/lib/release/lib -lcgraph -lcdt -lpython27 -lmsvcr90 -o build\lib.win32-2.7\py

Copy the contents of the build/lib.win32-2.7 directory(single sub-folder called pygraphviz) into your Python’s site-packages folder.

You can create a PNG image file called my_project_visualized.png with application grouping running the following command: graph_models -a -g -o my_project_visualized.png

Django Extensions
Graphviz website
PyGraphviz website
Minimalist GNU for Windows

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8 thoughts on “Installing PyGraphviz on Windows”
  • sushant says:

    I did what you have said above but it gives error as:
    “error: command ‘gcc’ failed no such file or directory”

    January 21, 2012 at 4:53 am
  • Ioan Seicean says:

    You didn’t add mingw/bin directory to the system path.

    March 13, 2012 at 2:47 pm
  • NY says:

    Hi, I follow the steps you introduce, and in the last part, I don’t understand this sentence.
    “Copy the contents of the build/lib.win32-2.7 directory(single sub-folder called pygraphviz) into your Python’s site-packages folder.”

    1, do you mean copy “C:pygraphviz-1.1uildlib.win32-2.7pygraphviz” this directory?
    2, what is Python’s site-packages folder?

    April 19, 2012 at 4:18 am
  • NY says:

    After following the steps you gave, I got the the install massage you paste there. Besides, it still gives error as:
    “c:/mingw/bin../lib/gcc/mingw32/4.5.0/../../../mingw32/bin/ld.exe: cannot find -lcgraph
    c:/mingw/bin../lib/gcc/mingw32/4.5.0/../../../mingw32/bin/ld.exe: cannot find -lcdt
    collect2: ld returned 1 exit status
    error: command ‘gcc’ failed with exit status 1”

    April 19, 2012 at 4:25 am
  • NY says:

    Sorry to trouble again, I know what the last sentence mean now, but I still have the error message, do you know how to deal with it?

    April 19, 2012 at 4:31 am
  • NY says:

    Hi, there, my problem have been solved, I just want to add if others still have the same problem here.

    If change the library path to
    library_path=’C:\Graphviz 2.28\lib\debug\lib’
    my install process would work successfully.

    April 19, 2012 at 7:54 am
    • Ioan Seicean says:

      I have installed PyGraphviz twice. First time I had the library_path similar to yours. After several months, when I had to do the steps again I didn’t remember which installer/build versions to use. So the second time I have stored this information in the article hoping that will be helpful for other people that run into the same issue.

      April 25, 2012 at 9:55 am
  • fei says:

    according to your method,but i failed to install setp,I am stuped,so what i can’t know do?
    I add mingw/bin directory to the system path and also apply to compiler = “gcc”, it gives error as:“error: command ‘gcc’ failed no such file or directory”.

    June 4, 2012 at 3:17 pm

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