图文详解Python中常用标准库(时间库、随机库、正则表达式)

import sys
print(sys.exec_prefix)   #获取python的安装路径

#标准库的导入方式
使#用保留字 from 和 import 导入相应标准库
import time
from time import sleep  #从time库中导入sleep（）函数
from time import * #全部导入

import time   #导入时间库
a = time.time() #time（）时间戳
print(a)

import time
strat = time.time()  #开始时间
i = 1
while i<100000000:  #该循环执行100000000
    i+=1
    print(i)
end = time.time()   #结束时间
print("开始时间：",strat,"结束时间：",end,"用时: ",end-strat)  #执行100000000次所需要的时间

#localtime()函数获取当前时间
import time
a=time.localtime()
print(list(a))
print(a)  #struct_time

import time
a = time.gmtime() #
print(a)

#ctime()
import time
a = time.ctime() #字符串形式的时间值
print(a)

 import time
 print(time.localtime())  #获取时间戳
 print(time.mktime(time.localtime()))

import time
a = time.localtime()
b = time.strftime('%Y-%m-%d-%H:%M:%S',a)
print(a,'\n',b)

import time
a = time.strptime('2021-09-30','%Y-%m-%d')
print(a)

import time
print('开始')
time.sleep(10)
print('此消息10秒后输出')

import random
a = random.uniform(1,5)
print(a)

import random
a = random.random()
print(a)

import random
a = random.randint(3,8)
print(a)

import random
a = random.randrange(0,20,5)
print(a)

import random
ls = ['一等奖','二等奖','三等奖','谢谢惠顾']
a = random.sample(ls,2)  #随机选择两个元素
print(a)

# 随机种子
# seed(种子)
import random
ls = ['一等奖','二等奖','三等奖','谢谢惠顾']
random.seed(100)  #种下种子后种下说明发什么芽
print((random.choice(ls))) #随机从ls中选择一个数据
random.seed(88) #一旦有了结果这个芽不会变
print(random.choice(ls))

import random
ls = ['一等奖','二等奖','三等奖','谢谢惠顾']
random.shuffle(ls)
print(ls)

import random
ls = ['一等奖','二等奖','三等奖','谢谢惠顾']
a = random.sample(ls,2)
print(a)

#     正则表达式
#  match(参数1,参数2) 功能：参数2 中查找满足参数1（正则表达式）的内容
import re
message = 'zs、l、w、z'
result = re.match('s',message) #起始位置找不到就找不到，开头就要匹配上
print(result)  #span表明匹配的位置

import re
message = '张三、李四、王二、赵六'
result = re.match('张三',message) #起始位置找不到就找不到，开头就要匹配上
print(result)  #span表明匹配的位置

import  re
message = '张三，李四，王五，赵六，王五'
result = re.search('五',message)
print(result)

import  re
message = '张三，李四，王五，赵六，王五'
result = re.findall('王五',message)
print(result)

import  re
message = 'Python93,C87,Java63,C++88'
result_1 = re.search('[cn]',message)
result_2 = re.findall('[0-9]',message)
result_3 = re.findall('[a-z][0-9][0-9]',message)
print(result_1,result_2,result_3)

import  re
message = 'da2a7ddre77yifed77t3fefd777b'
result = re.findall('[a-z]*[0-9][a-z]',message)
print(result)

import  re
message = 'da2a7ddre77yifed77t3fefd777b'
result = re.findall('[a-z]+[0-9][a-z]',message)  #+前面表达式要表达多次，数字前面必须带有字母
print(result)

import  re
message = 'da2a7ddre77yifed77t3fefd777b'
result = re.findall('[a-z]?[0-9][a-z]',message)  #+前面表达式要表达多次，数字前面必须带有字母
print(result)

import re
phone_num = input("shoujihao:")
result = re.findall('^1[0-9]{10}$',phone_num)
print(result)

import re
use_name = input("输入用户名：")
result = re.findall('^[A-Za-z_]\w{7,}$',use_name)
print(result)

import re
message = "verb very never every"
result = re.findall(r'\w+er\B',message)
print(result)

import re
message = "verb very never every"
result = re.findall('.e',message)
print(result)

import re
message= 'ccc74679955436hd'
result = re.findall('ccc\d+',message)
print(result)

import re
message= 'ccc74679955436hd'
result = re.findall('ccc\d+?',message)
print(result)

import re

text = "我喜欢苹果和香蕉"
pattern = r"苹果|香蕉"
result = re.findall(pattern, text)
print(result)  # 输出: ['苹果', '香蕉']

import re
pattern = r"(ab)+"
text = "ababab"
result = re.fullmatch(pattern, text)
print(result.group())  # 输出: ababab