# NumPy isdigit() function

In this tutorial, we will cover `isdigit()` function of the char module of the Numpy library.

The `isdigit()` function returns True if all the characters in the element are digits or numbers otherwise, this function returns False.

• This function calls `str.isdigit` on every element of the array.

• This function is locale-dependent for an 8-bit string.

### Syntax of `numpy.char.isdigit()`:

The syntax required to use this function is as follows:

``numpy.char.isdigit(arr)``

The above syntax indicates that `isdigit()` function takes a single parameter.

In the above syntax, the argument `arr` is mainly used to indicate the input array of strings on which this function will be applied.

Returned Values:

This function will return an output array of boolean values, with True and False values corresponding to every string element, based on whether the string contains only digits(number) or not.

## Example 1:

Below we have a simple code example, where we have used the `isdigit()` function with an array of strings, some of which only contain digit, where as some have other characters too:

``````import numpy as np

inp_ar = np.array([ '20002', '10009', '12345ab','01'] )
print("The Input string is:")
print(inp_ar)

x = np.char.isdigit(inp_ar)
print("The Output is:")
print(x)``````

The Input string is:
['20002' '10009' '12345ab' '01']
The Output is:
[ True True False True]

## Example 2:

In the code snippet we will use `isdigit()` function with array of strings, in which some strings have whitespaces and other characters(other than digits):

``````import numpy as np

inp_ar = np.array([ '20002 2', 'a10009', '12345 ab','01'] )
print("The Input string is:")
print(inp_ar)

x = np.char.isdigit(inp_ar)
print("The Output is:")
print(x)``````

The Input string is:
['20002 2' 'a10009' '12345 ab' '01']
The Output is:
[False False False True]

## Summary

In this tutorial we learned `isdigit()` function of the Numpy library. We covered how it is used with its syntax and values returned by this function along with some examples where we used the function.