# -*- coding: utf-8 -*-

# 导入正则表达式的库
import re

JieGuo1=re.search(r"17wx","www.17wx.net")
print(JieGuo1)
print(JieGuo1.span())

# 查找1个数字，\d
JieGuo2=re.search(r"\d","www.17wx.net")
print(JieGuo2)

# 查找2个数字，\d\d
JieGuo2=re.search(r"\d\d","www.17wx.net")
print(JieGuo2)

# 查找4个数字，\d\d\d
JieGuo3=re.search(r"\d\d\d","www.17wx.net")
print(JieGuo3)


——————————
输出结果：

<_sre.SRE_Match object; span=(4, 8), match='17wx'>
(4, 8)
<_sre.SRE_Match object; span=(4, 5), match='1'>
<_sre.SRE_Match object; span=(4, 6), match='17'>
None

Process finished with exit code 0