如何看一个python的模块是否安装了

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pip list

pip freeze

pip show <module_name>

pip search <module_name>

How to know if a python module is installed or not in the system: You can do a very easy test in terminal,

$ python -c "import math"
$ echo $?
0                                # math module exists in system

$ python -c "import numpy"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: No module named numpy
$ echo $?
1                                # numpy module does not exist in system

In case we do not want to unwantedly import a module in question (which would happen in a trystatement) we can make use of sys.modules to test modules that are installed and were imported before.

In the python shell issue:

>>> import sys

Then test for installed modules:

>>> ‘numpy‘ in sys.modules
True
>>> ‘scipy‘ in sys.modules
False

如何看一个python的模块是否安装了

标签：statement   wan   mina   and   iss   term   back   str   call   

原文地址：https://www.cnblogs.com/andy-0212/p/10198110.html