import re
db="mysql://root:fada@22ra017@127.0.0.1/htdb?charset=utf8mb4"
r = re.search("mysql:\/\/([^:]+):([^#]+)@((?:[0-9]{1,3}\.){3}[0-9]{1,3})/([^\?]+)\?charset=utf8", db)
print(r)
print(r.group(0))
print(r.group(1))
print(r.group(2))
print(r.group(3))
print(r.group(4))


C:\python3.7\python.exe D:/Python-Test/StuProject/comment/tests.py
<_sre.SRE_Match object; span=(0, 53), match='mysql://root:fada@22ra017@127.0.0.1/htdb?charset=>
mysql://root:fada@22ra017@127.0.0.1/htdb?charset=utf8
root
fada@22ra017
127.0.0.1
htdb