[FIXED] How to automatically determine type for user input?

Issue

I want to make a simple math function that takes user input, yet allows the user to not input an integer/float. I quickly learned Python does not identify type by default. Quick Google search shows using literal_eval, but it returns with ValueError: malformed string if a string is the input. This is what I have so far:

from ast import literal_eval

def distance_from_zero(x):
  if type(x) == int or type(x) == float:
    return abs(x)
  else:
    return "Not possible"

x = literal_eval(raw_input("Please try to enter a number "))

print distance_from_zero(x)

Solution

Like you mentioned you will get malformed string error (ValueError) if you get input like ast.literal_eval('c1'). You will also get SyntaxError if you do something like ast.literal_eval('1c'). You will want get the input data and then pass it to literal_eval. You can then catch both of these exceptions, and then return your 'Not Possible'.

from ast import literal_eval

def distance_from_zero(x):
    try:
        return abs(literal_eval(x))
    except (SyntaxError, ValueError):
        return 'Not possible'

    x = raw_input("Please try to enter a number ")

    print distance_from_zero(x)

Answered By - RJ7