1.模块
标准模块:不需要安装,可以直接导入的模块(库)
创建名为sys.py文件,执行该文件:
import sys print(sys.path)打印环境变量 (python2中执行这个命令会报错,因为在寻找sys模块的时候有限查找当前路径是否有,看到有sys.py就会引用,然后这个文件是我们自己创建的,里面并没有sys.path方法,python3中会输出正常结果) C:UsersAdministratorAppDataLocalProgramsPythonPython36-32python.exe C:/Users/Administrator/PycharmProjects/jinhailan/day2/sys.py ['C:\Users\Administrator\PycharmProjects\jinhailan\day2', 'C:\Users\Administrator\PycharmProjects\jinhailan', 'C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\python36.zip', 'C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\DLLs', 'C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\lib', 'C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32', 'C:\Users\Administrator\AppData\Local\Programs\Python\Python36-32\lib\site-packages'] Process finished with exit code 0
linux下执行:
In [15]: import sys In [16]: print(sys.path) ['', '/usr/bin', '/usr/lib64/python26.zip', '/usr/lib64/python2.6', '/usr/lib64/python2.6/plat-linux2', '/usr/lib64/python2.6/lib-tk', '/usr/lib64/python2.6/lib-old', '/usr/lib64/python2.6/lib-dynload', '/usr/lib64/python2.6/site-packages', '/usr/lib/python2.6/site-packages', '/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg-info', '/usr/lib/python2.6/site-packages/IPython/extensions']
python安装的第三方库一般都会存放在XXX\lib\site-packages中。
python标准库一般在XXX\lib目录中。
python导入或者自己调用一些库的时候就会在这个命令显示的路径中去找。