Best practice when constructing if statement based on datatype?

Question

I am constructing a basic function with an if statement based on datatype. I am wondering whether there is any problem with using:

if type(number) == int:

in something like:

def distance_from_zero(number):
"""Takes input 'number', checks datatype. If integer or floating point, returns absolute value. If other, returns 'Nope'"""
if type(number) == int:
    return abs(number)
elif type(number) == float:
    return abs(number)
else:
    return "Nope"

distance_from_zero(45)

Is there a cleaner/better way to use datatypes in if statements?

In the spirit of duck typing, it is considered bad form to check types explicitly. — stewSquared, Jun 04 '14 at 01:10

score 4 · Accepted Answer · answered Jun 04 '14 at 01:06

4

Why even check?

try:
    return abs(number)
except TypeError:
    return 'Nope'

answered Jun 04 '14 at 01:06

kylieCatt

9,293
4
39
50

score 2 · Answer 2 · answered Jun 04 '14 at 01:11

2

You can use isinstance()

if isinstance(number, (int, float)):
    return abs(number)

answered Jun 04 '14 at 01:11

Valentin Briukhanov

1,103
8
13

score 1 · Answer 3 · answered Jun 04 '14 at 01:00

1

I don't see any problem with that code, although you can write it more simply as:

if type(number) in (int, float):
    return abs(number)
else:
    return "Nope"

answered Jun 04 '14 at 01:00

Andy G

18,518
5
42
63

Best practice when constructing if statement based on datatype?

3 Answers3