python以下导入包的格式错误的是_python – Pydot错误：无法识别文件格式“png”...

我需要通过pydot构建一个

pythonic图解决方案,并尝试运行一个简单的代码,如：

import pydot

graph = pydot.Dot(graph_type='graph')

i=1

edge = pydot.Edge("A", "B%d" % i)

graph.add_edge(edge)

graph.write_png('graph.png')

这是为了在png文件上构建一个简单的图形(A-B1).

在解决了很多错误配置后,现在我得到了：

Traceback (most recent call last):

File "/Users/zallaricardo/Documents/Python/test_png.py", line 7, in

graph.write_png('graph.png')

File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 1809, in

lambda path, f=frmt, prog=self.prog : self.write(path, format=f, prog=prog))

File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 1911, in write

dot_fd.write(self.create(prog, format))

File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pydot.py", line 2023, in create

status, stderr_output) )

pydot.InvocationException: Program terminated with status: 1. stderr follows: Format: "png" not recognized. Use one of:

logout

直到现在还无法找到我特定环境的直接解决方案.

有关如何修复它的任何提示？

需要适用于python 2.7和mac os x 10.9.

我目前安装的包：

cycler==0.9.0

decorator==4.0.4

graphviz==0.4.7

matplotlib==1.5.0

networkx==1.10

numpy==1.10.1

pydot2==1.0.33

pyparsing==1.5.7

PyPDF2==1.25.1

python-dateutil==2.4.2

pytz==2015.7

six==1.10.0

wheel==0.26.0