[代码笔记] python 常用标准库学习

#!/usr/bin/python3
#文件名: demo_lib.py
#看看python的标准库(强大)

import re
import math
import random

#测试正则表达式
lst=re.findall(r'a[a-z]*','abcd aifg iigg ooaa nnva 9afg')
print(lst)

#测试math库
#help(math)

#测试random
print(random.choice([ x for x in range(20)]))

print(random.sample(range(100),10))

print(random.random())

for x in range(10):
    print(random.randrange(99))

from urllib.request import urlopen
#前方高能,非战斗人员请立即撤离
'''for line in urlopen('http://www.baidu.com'):
    line=line.decode('utf-8') #处理数据,转码显示
    print(line)
'''    

import smtplib#经过多次测试,表示还不会,放弃
'''server = smtplib.SMTP('smtp.126.com')
server.login('guddqs@126.com','************')
server.sendmail('guddqs@126.com', 'guddqs@qq.com',
"""To: guddqs@126.com
From: guddqs@qq.com
Hello ,Boys, You Validata No is : 998774
""")
server.quit()
'''

from datetime import date
now = date.today()
print(now)
print(now.strftime('%m-%d-%y. %d %b %Y is a %A on the %d day of %B.'))
#支持通过年月日建立一个时间实例
birthday=date(1997,7,2)
age= now - birthday
print(age.days//365)


#数据压缩
import zlib
s=b'fgfgfgfgfgfgfgfgfgfgfgfg fgfgfgfg gfgf gfg gfg'
print(len(s))
t=zlib.compress(s)
print(len(t))

st=zlib.decompress(t)
print(st)

print(zlib.crc32(s))

#性能度量
from timeit import Timer
t=Timer('for x in range(10):t=a;a=b;b=t','a=1;b=2').timeit()
print(t)
t2=Timer('for x in range(10):a,b=b,a','a=1;b=2').timeit()
print(t2)
print(t2-t)

#测试模块
def average(values):
    """Computes the arithmetic mean of a list of numbers.

    >>> print(average([20, 30, 70]))
    40.0
    """
    return sum(values) / len(values)

import doctest
print(doctest.testmod())   # 自动验证嵌入测试(将40.0改成30.0,将打印测试错误日志)