python string 0 not returning isnumeric true code example

Example 1: python check if number

if type(variable) == int or type(variable) == float:
    isNumber = True

Example 2: isnumeric python

str.isnumeric()
str = u"this2009";  
print str.isnumeric()
> False
str = u"23443434";
print str.isnumeric()
> True