如果你的浮点数始终以十进制表示，则类似于
>>> import re>>> re.findall("d+.d+", "Current Level: 13.4 db.")['13.4']可能就足够了。
一个更强大的版本是：
>>> re.findall(r"[-+]?d*.d+|d+", "Current Level: -13.2 db or 14.2 or 3")['-13.2', '14.2', '3']
如果要验证用户输入，也可以通过直接移至浮动来检查浮动：
user_input = "Current Level: 1e100 db"for token in user_input.split(): try: # if this succeeds, you have your (first) float print float(token), "is a float" except ValueError: print token, "is something else"# => Would print ...## Current is something else# Level: is something else# 1e+100 is a float# db is something else
