linux服务器导入python matplotlib.pyplot报错

在linux服务器端执行python脚本，有时候需要画图，但是linux没有GUI界面，因此需要在导入matplotlib.pyplot库之前先执行

import matplotlib as mpl

mpl.use('Agg')

再执行

import matplotlib.pyplot as plt

需要保存图片到指定的目录

plt.savefig("/home/yourname/test.jpg") 

如果直接执行import matplotlib.pyplot as plt会报错：

>>> import matplotlib.pyplot as plt
Traceback (most recent call last):
  File "", line 1, in
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/pyplot.py", line 115, in
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_qt5agg.py", line 16, in
    from .backend_qt5 import QtCore
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_qt5.py", line 26, in
    import matplotlib.backends.qt_editor.figureoptions as figureoptions
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/qt_editor/figureoptions.py", line 20, in
    import matplotlib.backends.qt_editor.formlayout as formlayout
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/qt_editor/formlayout.py", line 56, in
    from matplotlib.backends.qt_compat import QtGui, QtWidgets, QtCore
  File "/usr/anaconda2/lib/python2.7/site-packages/matplotlib/backends/qt_compat.py", line 137, in
    from PyQt4 import QtCore, QtGui
ImportError: No module named PyQt4