正则表达式match/search/findall/sub/split 等用法

import re
name = "abC123 efg"
name1 = "123abcD234"
name2 = "123 abcd 456 efgh 789"
# match 是从头开始匹配，但只匹配一次
pattern1 = re.compile("[a-z]+", re.S|re.I)
print(pattern1.match(name).group())

# search 是从任意位置匹配，仅匹配一次
pattern2 = re.compile("[a-z]+", re.S|re.I)
print(pattern2.search(name1).group())

# findall 查找符合正则的内容，返回所有结果 list
pattern3 = re.compile("\d+", re.S|re.I)
print(pattern3.findall(name1))

# sub替换字符串
pattern4 = re.compile("\d+", re.S|re.I)
print(pattern4.sub("*", name1))

# split拆分
pattern5 = re.compile(" ")
print(pattern5.split(name2))