[nowcoder53]表示数值的字符串

请实现一个函数用来判断字符串是否表示数值（包括整数和小数）。例如，字符串”+100”,”5e2”,”-123”,”3.1416”和”-1E-16”都表示数值。 但是”12e”,”1a3.14”,”1.2.3”,”+-5”和”12e+4.3”都不是。

# -*- coding:utf-8 -*-
class Solution:
# s字符串
def isNumeric(self, s):
    # write code here
    if(len(s)==0):
        return False
    ii=0
    li=[str(x) for x in range(10)]
    if(s[0] in ['+','-']):
        ii=1
    judge=0
    for i in range(ii,len(s)):
        if(s[i]=='.'):
            if(not judge):
                judge=1
            else:
                return False
        elif(s[i] in ['e','E']):
            i+=1
            if(i<len(s)):
                if(s[i] in ['+','-']+li):
                    i+=1
                    while(i<len(s)):
                        if(s[i] not in li):
                            return False
                        i+=1
                    break
                break
            else:
                return False
        elif(s[i] not in li):
            return False
    return True