Python常用Tips

• pip安装使用-i参数指定源

指定豆瓣源，快如闪电：pip install -i

• 使用sys.modules查看导入包的路径
  sys.modules是一个全局字典，可以通过它来了解当前环境加载了什么包，包的路径

>>> import sys
>>> print(sys.modules.keys()) # 查看加载的包
dict_keys(['builtins', 'sys', '_frozen_importlib', '_imp', '_warnings', '_thread', '_weakref', '_frozen_importlib_external', '_io', 'marshal', 'posix', 'zipimport', 'encodings', 'codecs', '_codecs', 'encodings.aliases', 'encodings.utf_8', '_signal', '__main__', 'encodings.latin_1', 'io', 'abc', '_weakrefset', 'site', 'os', 'errno', 'stat', '_stat', 'posixpath', 'genericpath', 'os.path', '_collections_abc', '_sitebuiltins', 'sysconfig', '_sysconfigdata_m_linux_x86_64-linux-gnu', '_bootlocale', '_locale', 'types', 'functools', '_functools', 'collections', 'operator', '_operator', 'keyword', 'heapq', '_heapq', 'itertools', 'reprlib', '_collections', 'weakref', 'collections.abc', 'importlib', 'importlib._bootstrap', 'importlib._bootstrap_external', 'warnings', 'importlib.util', 'importlib.abc', 'importlib.machinery', 'contextlib', 'zope', 'sitecustomize', 'apport_python_hook', 'readline', 'atexit', 'rlcompleter'])
>>> print(sys.modules.values())  # 查看路径
dict_values([<module 'builtins' (built-in)>, <module 'sys' (built-in)>, <module 'importlib._bootstrap' (frozen)>, <module '_imp' (built-in)>, <module '_warnings' (built-in)>, <module '_thread' (built-in)>, <module '_weakref' (built-in)>, <module 'importlib._bootstrap_external' (frozen)>, <module 'io' (built-in)>, <module 'marshal' (built-in)>, <module 'posix' (built-in)>, <module 'zipimport' (built-in)>, <module 'encodings' from '/usr/lib/python3.6/encodings/__init__.py'>, <module 'codecs' from '/usr/lib/python3.6/codecs.py'>, <module '_codecs' (built-in)>, <module 'encodings.aliases' from '/usr/lib/python3.6/encodings/aliases.py'>, <module 'encodings.utf_8' from '/usr/lib/python3.6/encodings/utf_8.py'>...
>>>import os
>>>print(sys.modules["os"]  # 查看指定包的路径
<module 'os' from '/usr/lib/python3.6/os.py'>