Python正则表达式如何进行字符串替换实例

result, number = re.subn(regex, newstring, subject)

rereobj = re.compile(regex)
result, number = reobj.subn(newstring, subject)

reresult = re.split(regex, subject)

rereobj = re.compile(regex)
result = reobj.split(subject)

if re.search(regex, subject):
do_something()
else:
do_anotherthing()

if re.match(regex, subject):
do_something()
else:
do_anotherthing()

match = re.search(regex, subject)
if match:
# match start: match.start()
# match end (exclusive): match.end()
# matched text: match.group()
do_something()
else:
do_anotherthing()