RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be 
able to function correctly if Python is not installed as a framework. See the Python 
documentation for more information on installing Python as a framework on Mac OS X. 
Please either reinstall Python as a framework, or try one of the other backends. If you 
are Working with Matplotlib in a virtual enviroment see 'Working with Matplotlib in 
Virtual environments' in the Matplotlib FAQ

      8 
      9 from matplotlib.widgets import Button
---> 10 import matplotlib.animation as animation
     11 from mpl_toolkits.mplot3d.axes3d import Axes3D
     12 

/Users/user/.virtualenvs/amiigo/lib/python2.7/site-packages/matplotlib/animation.py in <module>()
    415 # Combine FFMpeg options with pipe-based writing
    416 @writers.register('ffmpeg')
--> 417 class FFMpegWriter(MovieWriter, FFMpegBase):
    418     def _args(self):
    419         # Returns the command line parameters for subprocess to use

/Users/user/.virtualenvs/amiigo/lib/python2.7/site-packages/matplotlib/animation.py in wrapper(writerClass)
     64     def register(self, name):
     65         def wrapper(writerClass):
---> 66             if writerClass.isAvailable():
     67                 self.avail[name] = writerClass
     68             return writerClass

/Users/user/.virtualenvs/amiigo/lib/python2.7/site-packages/matplotlib/animation.py in isAvailable(cls)
    264                              stdout=subprocess.PIPE,
    265                              stderr=subprocess.PIPE,
--> 266                              creationflags=subprocess_creation_flags)
    267             p.communicate()
    268             return True

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags)
    708                                 p2cread, p2cwrite,
    709                                 c2pread, c2pwrite,
--> 710                                 errread, errwrite)
    711         except Exception:
    712             # Preserve original exception in case os.close raises.

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in _execute_child(self, args, executable, preexec_fn, close_fds, cwd, env, universal_newlines, startupinfo, creationflags, shell, to_close, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite)
   1332                     if e.errno != errno.ECHILD:
   1333                         raise
-> 1334                 child_exception = pickle.loads(data)
   1335                 raise child_exception
   1336 

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in loads(str)
   1380 def loads(str):
   1381     file = StringIO(str)
-> 1382     return Unpickler(file).load()
   1383 
   1384 # Doctest

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load(self)
    856             while 1:
    857                 key = read(1)
--> 858                 dispatch[key](self)
    859         except _Stop, stopinst:
    860             return stopinst.value

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load_string(self)
    964             if rep.startswith(q):
    965                 if len(rep) < 2 or not rep.endswith(q):
--> 966                     raise ValueError, "insecure string pickle"
    967                 rep = rep[len(q):-len(q)]
    968                 break

ValueError: insecure string pickle

      9 # Plotting
---> 10 import matplotlib.pyplot as plt
     11 import seaborn as sns
     12 

/usr/local/lib/python2.7/site-packages/matplotlib/pyplot.py in <module>()
    112 
    113 from matplotlib.backends import pylab_setup
--> 114 _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
    115 
    116 _IP_REGISTERED = None

/usr/local/lib/python2.7/site-packages/matplotlib/backends/__init__.pyc in pylab_setup()
     30     # imports. 0 means only perform absolute imports.
     31     backend_mod = __import__(backend_name,
---> 32                              globals(),locals(),[backend_name],0)
     33 
     34     # Things we pull in from all backends

/usr/local/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py in <module>()
     22 
     23 import matplotlib
---> 24 from matplotlib.backends import _macosx
     25 
     26 

RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be able to function correctly if Python is not installed as a framework. See the Python documentation for more information on installing Python as a framework on Mac OS X. Please either reinstall Python as a framework, or try one of the other backends. If you are Working with Matplotlib in a virtual enviroment see 'Working with Matplotlib in Virtual environments' in the Matplotlib FAQ

import subprocess32 as subprocess
p = subprocess.Popen(['foo'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
p.communicate()

$ python
Python 2.7.11 (default, Feb 16 2016, 17:51:10) 
[GCC 4.2.1 Compatible Apple LLVM 7.0.2 (clang-700.1.81)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess32 as subprocess
>>> p = subprocess.Popen(['foo'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/site-packages/subprocess32.py", line 825, in __init__
    restore_signals, start_new_session)
  File "/usr/local/lib/python2.7/site-packages/subprocess32.py", line 1574, in _execute_child
    raise child_exception_type(errno_num, err_msg)
OSError: [Errno 2] No such file or directory: 'foo'
>>> p.communicate()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'p' is not defined
>>> 

- Issue #26083: Workaround a subprocess bug that raises an incorrect
  "ValueError: insecure string pickle" exception instead of the actual
  exception on some platforms such as Mac OS X when an exception raised
  in the forked child process prior to the exec() was large enough that
  it overflowed the internal errpipe_read pipe buffer.