Can I use dtype to find the elements of an numpy array are strings?

Question

I got an numpy array, for example:

myArray = np.array(['a','bc'])

Is it possible use dtype to find out, whether its elements are strings？

The only way I can do is checking myArray.dtype == 'S2', but my Problem is I don't know in advance how many character are there in my elements.

Can I use something like myArray.dtype == 'str'?

Alex Riley · Accepted Answer · 2015-04-07 16:48:50Z

4

You could use issubdtype to do the checking:

>>> np.issubdtype(myArray.dtype, str)
True

The function checks whether a given dtype is ordered below another in NumPy's type hierarchy.

Alternatively, you could inspect the dtype's character code directly. String types have code 'S':

>>> myArray.dtype.char
'S'

answered Apr 7, 2015 at 16:40

Alex Riley

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1 Comment

+1 Wasn't aware of np.issubdtype, I was usually check this stuff as issubclass(myArray.dtype.type, str).