Re模块的 三个方法

import re

s1 = '绿茶白茶黄茶青茶红茶黑茶'
s2 = '中国绿茶白茶黄茶青茶红茶黑茶'

ret = re.findall(".茶", s1)
print(ret)

r1 = re.search(".茶", s1)
print("search方法直接返回", r1)
if r1:
    print(r1.group())

r21 = re.match(".茶", s1)
print("match方法直接返回", r21)
if r21:
    print(r21.group())
r22 = re.match(".茶", s2)
print("match方法直接返回", r22)
if r22:
    print(r22.group())

['绿茶', '白茶', '黄茶', '青茶', '红茶', '黑茶']
search方法直接返回 <re.Match object; span=(0, 2), match='绿茶'>
绿茶
match方法直接返回 <re.Match object; span=(0, 2), match='绿茶'>
绿茶
match方法直接返回 None

ret = re.findall(r"[\d|\.]", "40.237")
print(ret)   # ['4', '0', '.', '2', '3', '7']

ret = re.findall(r"[\d|\.]+", "40.237")
print(ret)  # ['40.237']

ret = re.findall(r"[\d|\.]+", "2020-10-10 11:12:40.237")
print(ret)  # ['2020', '10', '10', '11', '12', '40.237']