正则表达式基础补充学习

import re
 
str = 'Hi \n _12'
print(str)

一、除换行符之外的任意字符

print(re.findall(".",str))
# 连着两个
print(re.findall("..",str))
# 连着三个
print(re.findall("...",str))
print(re.findall("....",str))

二、 字母、数字、下划线

print(re.findall("\w", str))
# 连着两个
print(re.findall("\w\w", str))
# 连着三个
print(re.findall("\w\w\w", str))

三、数字

print(re.findall("\d", str))

四、空格、换行符

print(re.findall("\s", str))

五、非字母、数字、下划线

print(re.findall("\W", str))

六、非数字

print(re.findall("\D", str))

七、非空格、换行符

print(re.findall("\S", str))

例：

str2 = 'Hello World 123'
 
print(re.findall('e', str2))
print(re.findall('ll', str2))
print(re.findall('l\n', str2))
print(re.findall('[abcd]', str2))
print(re.findall('[12][12]', str2))
print(re.findall('[12]..', str2))
print(re.findall('[a-f]', str2))
print(re.findall('[0-2a-e]', str2))
print(re.findall('[^a-e]', str2))

str3 = '122333 abbccc'
 
print(re.findall("\d{3}", str3))
print(re.findall("\w{3}", str3))
print(re.findall("1*", str3))
print(re.findall("1*2", str3))
print(re.findall("1*3", str3))
print(re.findall("1+", str3))
print(re.findall("1+2", str3))
print(re.findall("1+3", str3))
print(re.findall("\d*", str3))
print(re.findall("\d+", str3))
print(re.findall("\d+3", str3))

import re 
str = 'X1Y22Y333Y4444'
 
# 贪婪匹配
print(re.findall("X.*Y",str))
# ['X1Y22Y33Y']
 
# 惰性匹配
print(re.findall("X.*?Y",str))
# ['X1Y']
 
print(re.findall("\d*Y",str))
# ['1Y22Y333Y']
print(re.findall("\d.*?Y",str))
# ['1Y','22Y','333Y']

str2 = 'Hello World 123'
 
exp = re.compile('\w+')
print(exp.findall(str2))

str3 = 'My name is Martini!'
exp = re.compile('is (.*)!')
print(exp.findall(str3))
 
 
str4 = 'My name is Martini!My name is Sam!My name is Tom!'
# exp = re.compile('is (.*)!')
# exp = re.compile('is (.*?)!')
print(exp.findall(str4))
 
 
str5 = '''
My name is Martini,and i am 25 years old!
My name is Sam,and i am 27 years old!
My name is Tom,and i am 23 years old!'
exp = re.compile('is (.*?),.*?am (\d+)')
# print(exp.findall(str5))
for i,j in exp.findall(str5):
    print(i,j)