Question

Is there a way to check from a users input what type it is? and do something like so:

if input == str:
   do this
elif input == int:
   do this
else:
   do this

Answer 1

You can use isinstance to check the type of something — But you really probably don’t want to do this …

This also depends a lot on how you’re getting the input from the user. If you’re using raw_input, then it is always a string and you’ll need to try to convert it to whatever type you want:

try:
   x = int(input):
except ValueError:
   try:
       x = float(input):
   except ValueError:
       print "No recognizable type!"

One basic principle of python is duck-typing. If an object looks like a duck, sounds like a duck and smells like a duck, then it’s a duck (provided you only care what the object looks, smells and sounds like). Ultimately, in python it’s best to try something to see if it is a “duck”. If it isn’t a duck, then you catch the Exception and handle it (if you know how). This is the primary reason you don’t see people using isinstance very much in their code and the reason I warn against using it.