# numpy string operations | isdecimal() function

Last Updated : 14 Jan, 2019

`numpy.core.defchararray.isdecimal(arr) ` function returns True for each element if there are only decimal characters in the element.It returns false otherwise.

Parameters:
arr : array_like of str or unicode.

Returns : [ndarray] Output array of bools.

Code #1 :

 `# Python program explaining ` `# numpy.char.isdecimal() method  ` ` `  `import` `numpy as geek ` ` `  `# input array contains only digits ` `in_arr ``=` `geek.array([ ``'1000'``, ``'2000'``] ) ` `print` `(``"Input array : "``, in_arr)  ` ` `  `out_arr ``=` `geek.char.isdecimal(in_arr) ` `print` `(``"Output array: "``, out_arr) `

Output:

```Input array :  ['1000' '2000']
Output array:  [ True  True]
```

Code #2 :

 `# Python program explaining ` `# numpy.char.isdecimal() method  ` ` `  `import` `numpy as geek ` ` `  `# input array contains digits along with space and alphabets ` `in_arr ``=` `geek.array([ ``'1000 2'``, ``'a1000'``, ``'1234 ab'``] ) ` `print` `(``"Input array : "``, in_arr)  ` ` `  `out_arr ``=` `geek.char.isdecimal(in_arr) ` `print` `(``"Output array: "``, out_arr) `

Output:

```Input array :  ['1000 2' 'a1000' '1234 ab']
Output array:  [False False False]
```