If conditional that checks on variable type (int, float, ect)

Question

Python3: I wish to know if I can set up an if statement to execute some code just like one normally would.

But I want the statement to go something like this: (psudo-code)

If variable1 !== "variable type integer":
    then break.

Is this possible? Thanks for the help.

I apologize if this has already been addressed, but the search suggester bot didn't have any posts to point me to.

Jesse, NOOb

looks like javascript? You should add a Python3 tag to your post — Red Cricket, Feb 09 '15 at 05:57
possible duplicate of [What is the best (idiomatic) way to check the type of a Python variable?](http://stackoverflow.com/questions/378927/what-is-the-best-idiomatic-way-to-check-the-type-of-a-python-variable) — Burhan Khalid, Feb 09 '15 at 06:34
This is not a common pattern in Python - why do you think you need to do this? — Burhan Khalid, Feb 09 '15 at 06:34

score 4 · Answer 1 · answered Feb 09 '15 at 06:00

Usually it's better to use isinstance, so you accept variables that quack like ducks, too:

>>> isinstance(3.14, int)
False
>>> isinstance(4, int)
True
>>> class foo(int):
...     def bar(self):
...         pass
... 
>>> f = foo()
>>> isinstance(f, int)
True

paxdiablo · Answer 2 · 2015-02-09T06:11:35.273

0

You can import the types and check variables against them:

>>> from types import *

>>> answer = 42

>>> pi = 3.14159

>>> type(answer) is int # IntType for Python2
True

>>> type(pi) is int
False

>>> type(pi) is float # FloatType for Python 2
True

For your more specific case, you would use something like:

if type(variable1) is int:
    print "It's an int"
else:
    print "It isn't"

Just keep in mind that this is for a variable that already exists as the correct type.

If, as you may be indicating in your comment (if user_input !== "input that is numeric"), your intent is to try and figure out whether what a user entered is valid for a given type, you should try a different way, something along the lines of:

xstr = "123.4"             # would use input() usually.
try:
    int(xstr)              # or float(xstr)
except ValueError:
    print ('not int')      # or 'not float'

edited Feb 09 '15 at 06:11

answered Feb 09 '15 at 05:57

paxdiablo

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isnt pi a float type? And if I understand you correctly, this is pulling from a "types" module? Basically I just need a way of executing a break statement by using an if. if user_input !== "input that is numeric" – 11thZone Feb 09 '15 at 06:02
@user3321476, yes, it's a float type, which is why `type(pi) is int` gave you false. I've added the Python3-specific ones, relegating Python2 to comments, and given a more concrete example for you at the bottom. – paxdiablo Feb 09 '15 at 06:04
sweet, i get it now, you rock! – 11thZone Feb 09 '15 at 06:07
@user3321476, hopefully, I'll rock enough to get an upvote and/or accept. Nudge nudge, wink, wink :-) – paxdiablo Feb 09 '15 at 06:17

If conditional that checks on variable type (int, float, ect)

2 Answers2