Validate if a given string is numeric.

Some examples:
"0" => true
" 0.1 " => true
"abc" => false
"1 a" => false
"2e10" => true

Note: It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one.

class Solution:    # @param s, a string    # @return a boolean    def isNumber(self, s):        try:            float(s)                             return True                        except:            return False

Valid Number