Python 判断一个字符串是否是数字

How do I check if a string is a number (float) in Python?

http://stackoverflow.com/questions/354038/how-do-i-check-if-a-string-is-a-number-float-in-python

def is_number(s):
    try:
        float(s)
        return True
    except ValueError:
        return False