Steven C. Howell - 7 months ago 46
Python Question

# In Python, how would you check if a number is one of the integer types?

In Python, how could you check if the type of a number is an integer without checking each integer type, i.e.,

`'int'`
,
`'numpy.int32'`
, or
`'numpy.int64'`
?

I thought to try
`if int(val) == val`
but this does not work when a float is set to an integer value (not type).

``````In [1]: vals = [3, np.ones(1, dtype=np.int32)[0], np.zeros(1, dtype=np.int64)[0], np.ones(1)[0]]
In [2]: for val in vals:
...:     print(type(val))
...:     if int(val) == val:
...:         print('{} is an int'.format(val))
<class 'int'>
3 is an int
<class 'numpy.int32'>
1 is an int
<class 'numpy.int64'>
0 is an int
<class 'numpy.float64'>
1.0 is an int
``````

I want to filter out the last value, which is a
`numpy.float64`
.

You can use `isinstance` with a tuple argument with the types of interest:

``````>>> [(e, type(e), isinstance(e, (int, np.integer))) for e in vals]
[(3, <type 'int'>, True),
(1, <type 'numpy.int32'>, True),
(0, <type 'numpy.int64'>, True),
(1.0, <type 'numpy.float64'>, False)]
``````

Find only int and int64:

``````>>> [(e, type(e), isinstance(e, (int, np.int64))) for e in vals]
[(3, <type 'int'>, True), (1, <type 'numpy.int32'>, False), (0, <type 'numpy.int64'>, True), (1.0, <type 'numpy.float64'>, False)]
``````