ImportError: DLL load failed: 找不到指定的模块。

在导入matplotlib时出现找不到指定的模块问题，但确实安装了matplotlib库

 import matplotlib.pyplot as plt

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\87316\AppData\Local\Programs\Python\Python37\lib\site-packages\matplotlib\__init__.py", line 200, in <module>
    _check_versions()
  File "C:\Users\87316\AppData\Local\Programs\Python\Python37\lib\site-packages\matplotlib\__init__.py", line 194, in _check_versions
    module = importlib.import_module(modname)
  File "C:\Users\87316\AppData\Local\Programs\Python\Python37\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: DLL load failed: 找不到指定的模块。

　　解决办法：

step1：查看先前下载版本

pip show matplotlib          #如果Version: 3.1.0

step2：安装version=2.2.2版本

pip install matplotlib==2.2.2<br>’’’
Name: matplotlib
Version: 2.2.2
Summary: Python plotting package
Home-page: http://matplotlib.org
Author: John D. Hunter, Michael Droettboom
Author-email: matplotlib-users@python.org
License: BSD
Location: c:\users\87316\appdata\local\programs\python\python37\lib\site-packages
Requires: cycler, kiwisolver, pyparsing, numpy, six, pytz, python-dateutil
Required-by:
 
-javaagent:D:\course content\java\new\ideaIU-2018.1.5.win\bin\JetbrainsCrack-2.9-release-enc.jar
 
‘‘‘