Python正则

# !/user/bin/python
# -*- coding: utf-8 -*-

import re
# match, 从头开始匹配
a = re.match("192", "inet 地址:192.168.12.44")  # 不匹配, 因为字符串开头不是192.
b = re.match("inet", "inet 地址:192.168.12.44")  # 返回<_sre.SRE_Match object; span=(0, 4), match=‘inet‘>
print(a)
print(b)
print(b.group())  # 返回所有匹配的值.

# 点代表除了\n  之外的任意字符
c = re.match(".+", "inet 地址:192.168.12.44")
print(c)


# /w需要至少匹配一次
d = re.match("/w?", "inet 地址:192.168.12.44")
print(d)


# ?代表匹配一次或零次
d = re.match("/w?", "inet 地址:192.168.12.44")
print(d)

# search 搜索; groups可对字符串中的字符分组
e = re.search("(abc){2}a(123|456)c", "abcabca456c")
print(e.group())  # 返回abcabca456c
print(e.groups())  # 返回(‘abc‘, ‘456‘)

f = re.search("(\d\d)(\d\d)(\d){2}(\d){4}", "370218198709279908")
print(f.groups())  # (\d\d) 的形式会把匹配的字符都连起来写; (\d){4}的形式会把最后一个字符单个写出来.
                   # 返回(‘37‘, ‘02‘, ‘8‘, ‘7‘).
h = re.search("(\d{2})(\d{2})(\d{2})(\d{4})(\d{4})", "370218198709279908")
print(h.groups())  # 返回(‘37‘, ‘02‘, ‘18‘, ‘1987‘, ‘0927‘). 把字符串分组


# A 只从字符开头进行匹配
i = re.search("\Aa", "abcabca456c")
print(i.group())  # 返回a


# ^ 以指定字符/数字开头, 和A的作用一样
g = re.search("^37", "370218198709279908")
print(g.group())  # 返回37


# # groupdict 以字典的形式返回匹配的字符串
# k = re.search("(?P<province>[0,9]{4})(?P<city>[0,9]{2})(?P<birthday>[0,9]{4})", "370218198709279908")
# print(k.groupdict())  # TODO 为什么返回AttributeError: ‘NoneType‘ object has no attribute ‘groupdict‘,演示是在Xshell5环境


# # 搜索IP地址
# m = re.search("\d{1,3)\.\d{1,3}\.\d{1,3}\.\d{1,3}", "inet 地址:192.168.12.44") # TODO 为什么报错. 演示是在Xshell5环境
# print(m)
# n = re.search("(\d{1,3)\.){3}", "inet 地址:192.168.12.44")
# print(n)


# findall
o = re.findall("\d+","abcdfewage25435r3")
print(o)  #返回[‘25435‘, ‘3‘]

p = re.findall("[a-zA-Z]+]", "abjvldAFEWdfh2894AJlfd89AHvhk")
print(p)

q = re.findall("\D+]", "abjvldAFEWdfh2894AJlfd89AHvhk")
print(q)


# sub 替换
r = re.sub("\d+","|","abjvldAFEWdfh2894AJlfd89AHvhk" )  # 将数字替换成|
print(r)  # 返回 abjvldAFEWdfh|AJlfd|AHvhk


# split 拆分
s = re.split("\\\\", r‘c:\user\data\python35‘)
print(s)  # 返回 [‘c:‘, ‘user‘, ‘data‘, ‘python35‘]