Python的标准库有：

Python常用的第三方库有：

标准库用法参考示例：

datetime库：

为日期和时间处理同时提供方法。

from datetime import date

#导入时间库

now=date.today()

#取当前时间

print(now)

birthday=date(1987,12,3)

print(birthday)

age=now-birthday

#假设年龄=当前日期-生日日期

print(age)

运行结果为：

2019-05-04
1987-12-03
11475 days, 0:00:00

zlib库：

提供压缩和解压的功能。

import zlib

m = b'This is a test compress'

print(m)

m1=len(m)

#查看字符串的长度

print(m1)

t = zlib.compress(m)

#假设压缩后的内容为t

t1=len(t)

#查看压缩后内容t的长度

print(t)

print(t1)

s = zlib.decompress(t)

#解压缩后的内容为s

print(s)

运行结果为：

b'This is a test compress'
23
b'x\x9c\x0b\xc9\xc8,V\x00\xa2D\x85\x92\xd4\xe2\x12\x85\xe4\xfc\xdc\x82\xa2\xd4\xe2b\x00ah\x08\x82'
29
b'This is a test compress'

sys库：

调用命令行参数，经常使用sys.path来查看python及系统的依赖库包安装路径。

import sys

a=sys.path

#假设系统路径为a

print(a)

运行结果为：

['/Users/alice/PycharmProjects/untitled', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/nose-1.3.7-py2.7.egg', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/tornado-5.0.2-py2.7-macosx-10.13-intel.egg', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/backports_abc-0.5-py2.7.egg', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/singledispatch-3.4.0.3-py2.7.egg', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/futures-3.2.0-py2.7.egg', '/Users/alice/PycharmProjects/untitled', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python37.zip', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/lib-dynload', '/Users/alice/venv/untitled/lib/python3.7/site-packages', '/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages', '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python', '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC']

声明：https://blog.csdn.net/alice_tl/article/details/89815949