Pygraphviz / Python3 / Mac：TypeError

Question

我一直在尝试让Pygraphviz在Mac上使用Python3，但我无法解决TypeError。

具体来说，以下代码的输出（Python3 / Eclipse Neon / macOS 10.10.5，从此处改编的教程）

import networkx as nx
import queueing_tool as qt
import pygraphviz as pgv

a = pgv.AGraph()
print(a._get_prog('fdp'))

g = qt.generate_random_graph(200, seed=3)
q = qt.QueueNetwork(g, seed=3)
q.max_agents = 20000
q.initialize(100)
q.simulate(10000)

pos = nx.nx_agraph.graphviz_layout(g.to_undirected(), prog='neato')

是以下错误：

/usr/local/bin/fdp //<-- this shows that Eclipse finds 'fdp' after adding /usr/local/bin to $PATH, ERROR in the following:
Traceback (most recent call last):
  File "/Users/flurin/Documents/workspace/pedQN/main.py", line 14, in <module>
    pos = nx.nx_agraph.graphviz_layout(g.to_undirected(), prog='neato')
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/networkx/drawing/nx_agraph.py", line 228, in graphviz_layout
    return pygraphviz_layout(G,prog=prog,root=root,args=args)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/networkx/drawing/nx_agraph.py", line 262, in pygraphviz_layout
    A.layout(prog=prog,args=args)
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pygraphviz/agraph.py", line 1358, in layout
    data = self._run_prog(prog, ' '.join([args, "-T", fmt]))
  File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/pygraphviz/agraph.py", line 1338, in _run_prog
    warnings.warn(b"".join(errors), RuntimeWarning)
TypeError: cannot use a string pattern on a bytes-like object

如果我使用Python 2.7.x运行相同的代码（仅需要将'print（arg）'更改为'print arg'），我将得到以下输出（大量警告，但可以正常工作）：

/usr/local/bin/fdp
/usr/local/lib/python2.7/site-packages/pygraphviz/agraph.py:1338: RuntimeWarning: Warning: node 0, position [ 5.50797903  7.08147823], expected two floats
Warning: node 12, position [ 5.44649018  7.80314765], expected two floats
[... here other warnings of the same kind]
Warning: Overlap value "prism" unsupported - ignored

  warnings.warn(b"".join(errors), RuntimeWarning)

所以我的问题是，我怎样才能让pygraphviz也能与Python3一起使用？ 我不知道在哪里看。 请注意，从终端或Eclipse运行上述代码时得到的错误没有区别。

与Python3不兼容吗？ 我记得几年前曾被告知，出于“科学目的”，使用Python2.x可能更好。 还是这样吗？

非常感谢您的提前帮助！

Answer 1

在python 3中出现的graphviz错误的字节/字符串处理中有一个错误，该错误已包含在pygraphviz github master分支中（ https://github.com/pygraphviz/pygraphviz/pull/104 ）。 您可以从https://github.com/pygraphviz/pygraphviz下载该文件，直到发布新版本为止。

nb pygraphviz可在Python3上正常工作。