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numpy string operations | zfill() function
• Last Updated : 28 Jan, 2019

`numpy.core.defchararray.zfill(arr, width)` is another function for doing string operations in numpy. For each element in the array it returns the numeric string left-filled with zeros.The number of left filled zeros happen according to the width.

Parameters:
arr : array_like of str or unicode.Input array.
width : [int] The final width of the string after filling zeros.

Returns : [ndarray] Output array of str or unicode, depending on input type.

Code #1 :

 `# Python program explaining``# numpy.char.zfill() method `` ` `# importing numpy ``import` `numpy as geek`` ` `# input array  ``in_arr ``=` `geek.array([``'Geeks'``, ``'for'``, ``'Geeks'``])``print` `(``"Input array : "``, in_arr) `` ` `# setting the width of each string to 8``width ``=` `8`` ` `# output array``out_arr ``=` `geek.char.zfill(in_arr, width)``print` `(``"Output array: "``, out_arr) `
Output:

```Input array :  ['Geeks' 'for' 'Geeks']
Output array:  ['000Geeks' '00000for' '000Geeks']
```

Code #2 :

 `# Python program explaining``# numpy.char.zfill() method `` ` `# importing numpy ``import` `numpy as geek`` ` `# input array  ``in_arr ``=` `geek.array([``'1'``, ``'11'``, ``'111'``])``print` `(``"Input array : "``, in_arr)`` ` `# setting the width of each string to 5``width ``=` `5`` ` `# output array``out_arr ``=` `geek.char.zfill(in_arr, width)``print` `(``"Output array: "``, out_arr) `
Output:
```Input array :  ['1' '11' '111']
Output array:  ['00001' '00011' '00111']
```

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