初识正则表达式

a=re.findall(r"(123)(asd)\1","123asd123")
b=re.findall(r"(123)(asd)(123)","123asd123")
c=re.findall(r"(123)(asd)123","123asd123")
d=re.findall(r"(123)(asd)","123asd123")
print(a)
print(b)
print(c)
print(d)
[(‘123‘, ‘asd‘)]
[(‘123‘, ‘asd‘, ‘123‘)]
[(‘123‘, ‘asd‘)]
[(‘123‘, ‘asd‘)]

import re
a=re.search(r"(123)(asd)\1","123asd123").group()
b=re.search(r"(123)(asd)(123)","123asd123").group()
c=re.search(r"(123)(asd)123","123asd123").group()
d=re.search(r"(123)(asd)","123asd123").group()
print(a)
print(b)
print(c)
123asd123
123asd123
123asd123
123asd

import re
a="hello alex asd hello"
b=re.match("(h)\w+",a).group()
print(b)

hello

import re
a="hello alex asd hello"
b=re.match("(h)(e)\w+",a).groups()
print(b)

(‘h‘, ‘e‘)

import re
a="hello alex asd hello"
b=re.match("(?P<n1>h)(?P<n2>e)\w+",a).groupdict()    #其中P为大写
print(b)

{‘n2‘: ‘e‘, ‘n1‘: ‘h‘}    

import re
a="hello alex asd hello"
b=re.findall("a(?:l)ex",a)
print(b)

[‘alex‘]

import re
a="1a2s3d4f5"
b=re.findall("\d\w\d",a)
print(b)

[‘1a2‘, ‘3d4‘]

import re
a="12345"
b=re.findall("",a)
print(b)

[‘‘, ‘‘, ‘‘, ‘‘, ‘‘, ‘‘]            #里面6个空

import re
a="asd  alex  123  alex"
b=re.findall("(a)(\w(e))(x)",a)     #先提取第一个组中a，再提取第二组中le 再提取组中组e再提取组x
print(b)

[(‘a‘, ‘le‘, ‘e‘, ‘x‘), (‘a‘, ‘le‘, ‘e‘, ‘x‘)]　　　　#从左到右，从外到内的提取

import re
a="alex"
b=re.findall("(\w)(\w)(\w)(\w)",a)　　#有几个组提取几个内容
c=re.findall("(\w){4}",a)　　　　　　　 #一个组里面的内容出现四次，默认去最后一个内容
print(b)
print(c)

[(‘a‘, ‘l‘, ‘e‘, ‘x‘)]
[‘x‘]

import re
re.sub("g.t","have",‘I get A,  I got B ,I gut C‘，2)
I have A,  I have B ,I gut C

import re
print(re.subn("g.t","have",‘I get A,  I got B ,I gut C‘))
(‘I have A,  I have B ,I have C‘, 3)

import re
text = "JGood is a handsome boy,he is cool, clever, and so on..."
regex = re.compile(r‘\w*oo\w*‘)
print (regex.findall(text) )  #查找所有包含‘oo‘的单词
[‘JGood‘, ‘cool‘]

import re
print(re.split(‘\d+‘,‘one12two2three3four4‘))
[‘one‘, ‘two‘, ‘three‘, ‘four‘, ‘‘]

import re
print(re.split(‘a‘,‘1A1a2a3‘,flags=re.I))　　　　　#如果直接写re.I 默认把其放到第三位，不能起到作用
[‘1‘, ‘1‘, ‘2‘, ‘3‘]

import re
a="asd123asd156asd"
c=re.split("(1)(\d+)",a)
print(c)

[‘asd‘, ‘1‘, ‘23‘, ‘asd‘, ‘1‘, ‘56‘, ‘asd‘]

import re
iterator = re.finditer(r‘\d+‘,‘2g3g4g5g6g‘)
iterator1 = re.findall(r‘\d+‘,‘2g3g4g5g6g‘)
print(iterator)
print(iterator1)
for match in iterator:
     print(match.group(), match.span())
<callable_iterator object at 0x0000008310911128>
[‘2‘, ‘3‘, ‘4‘, ‘5‘, ‘6‘]
2 (0, 1)
3 (2, 3)
4 (4, 5)
5 (6, 7)
6 (8, 9)

import re
print(re.findall(r"a(\d+)", "a23b"))   #贪婪模式
print(re.findall(r"a(\d+?)", "a23b")) # 非贪婪模式
print(re.findall(r"a(\d+?)b","a23b"))  #前后有限定条件 非贪婪模式失效
[‘23‘]
[‘2‘]
[‘23‘]

import re
print(re.findall(r"a(\d+)b", "a23b"))　　　　　　#获取组()中的文件
print(re.search(r"a(\d+)b", "a23b").group())
print(re.match(r"a(\d+)b", "a23b").group())
[‘23‘]
a23b
a23b

import re
a=re.findall(r"(?:123)(?:asd)123","123asd123")
print(a)
[‘123asd123‘]

import re
print(re.search(r"m(alex)(eric)com\2m","mmalexericcomericmmm").group())      #默认group中参数为0
print(re.search(r"m(alex)(eric)com\2m","mmalexericcomericmmm").group(1))    #调取第一个组的内容
print(re.search(r"m(alex)(eric)com\2m","mmalexericcomericmmm").group(2))    #调取第二个组的内容
print(re.match(r"m(alex)(eric)com\2m","malexericcomericmmm").group())       #其中\2只是代表了第二组的内容，而没有括号
print(re.match(r"m(alex)(eric)com\2m","malexericcomericmmm").group(1))
print(re.match(r"m(alex)(eric)com\2m","malexericcomericmmm").group(2))
print(re.findall(r"m(alex)(eric)com(eric)m","malexericcomericmmm"))
malexericcomericm
alex
eric
malexericcomericm
alex
eric
[(‘alex‘, ‘eric‘, ‘eric‘)]

import hashlib

# ######## md5 ########
hash = hashlib.md5()
# help(hash.update)
hash.update(bytes(‘admin‘, encoding=‘utf-8‘))
print(hash.hexdigest())
print(hash.digest())


######## sha1 ########

hash = hashlib.sha1()
hash.update(bytes(‘admin‘, encoding=‘utf-8‘))
print(hash.hexdigest())

# ######## sha256 ########

hash = hashlib.sha256()
hash.update(bytes(‘admin‘, encoding=‘utf-8‘))
print(hash.hexdigest())


# ######## sha384 ########

hash = hashlib.sha384()
hash.update(bytes(‘admin‘, encoding=‘utf-8‘))
print(hash.hexdigest())

# ######## sha512 ########

hash = hashlib.sha512()
hash.update(bytes(‘admin‘, encoding=‘utf-8‘))
print(hash.hexdigest())