# -*- coding:utf-8 -*-

import re

class Solution:

# s字符串

def isNumeric2(self,s):

pa = r'^[\+\-]?[0-9]*(\.[0-9]*)?([eE][\+\-]?[0-9]+)?$'

pattern= re.compile(pa)

if re.match(pattern,s)!=None:

return True

else:

return False

def isNumeric3(self, s):

try:

float(s)

print s

if s[0:2]!='-+' and s[0:2]!='+-':

return True

else:

return False

except:

return False

def isNumeric(self, s):

# write code here

if s == None or len(s) <= 0:

return False

i = 0

digit = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

if s[0] == '+' or s [0] == '-':

i += 1

if i >= len(s):

return False

if self.findonly0(s[i:]):

return False

dig = self.scanDigit(s[i:])

i += dig

if i < len(s):

if s[i] == '.':

i += 1

dig = self.scanDigit(s[i:])

i += dig

else:

return True

if i < len(s):

if s[i] == 'e' or s[i] == 'E':

i += 1

if i >= len(s):

return False

if s[i] == '+' or s[i] == '-':

i += 1

if self.findonly0(s[i:]):

return False

else:

dig = self.scanDigit(s[i:])

if dig == 0:

return False

else:

i += dig

else:

dig = self.scanDigit(s[i:])

i += dig

else:

return True

return i == len(s)

def scanDigit(self, s):

i = 0

if s == None or len(s) == 0:

return 0

digit = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

while i<len(s) and (s[i] in digit):

i += 1

return i

def findonly0(self,s):

if s==None or len(s) == 0:

return False

if len(s)==1 and s[0] == '0':

return True

digit = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

if s[0] == '0' and s[1] in digit:

return True

else:

return False

s=Solution()

print s.isNumeric3('+100') #True

print s.isNumeric3('5e2') #True

print s.isNumeric3('-123') #True

print s.isNumeric3('3.1415') #True

print s.isNumeric3('-1e-16') #True

print s.isNumeric3('12E') #False

print s.isNumeric3('1a3.14') #False

print s.isNumeric3('123.45') #True

print s.isNumeric3('123.45e') #False

print s.isNumeric3('-.123') #True

print s.isNumeric3('123.45e+6') #True