How to check if all elements of a numpy.array are of the same data type?

Question

I have few numpy arrays, which can be formatted as

[1.525, 2.565, 6.367, ...]  # elements are float numbers

or

['', '', '', ...]  # elements are empty strings

I'd like to find out if all the elements in an array are of the same data type.

For now, I am using:

if isinstance(np.any(time_serie),float):
    return sum(time_serie)

But this one doesn't work. I got following error:

TypeError: cannot perform reduce with flexible type

So, may I know how to work around this? Thanks.

Answer 1

If you're looking for a particular data-type as provided in your example, e.g. all items are floats, then a map and reduce will do the trick:

>>> x = [1.525, 2.565, 6.367]

>>> all(map(lambda i: isinstance(i, float), x))
    True

>>> x = [1.525, 2.565, '6.367']

>>> all(map(lambda i: isinstance(i, float), x))
    False

Answer 2

You might want to use a list comprehension or map() for creating a sequence of data types, then make a set from this sequence and see if the length of the set is 1.