# numpy.append() in Python

• Last Updated : 04 Dec, 2020

The numpy.append() appends values along the mentioned axis at the end of the array
Syntax :

`numpy.append(array, values, axis = None)`

Parameters :

```array   : [array_like]Input array.
values  : [array_like]values to be added in the arr. Values should be
shaped so that arr[...,obj,...] = values. If the axis is defined values can be of any
shape as it will be flattened before use.
axis    : Axis along which we want to insert the values. By default, array
is flattened.
```

Return :

```An copy of array with values being appended at the end as per the mentioned object
along a given axis.
```

Code 1 : Appending arrays

 `# Python Program illustrating``# numpy.append()`` ` `import` `numpy as geek`` ` `#Working on 1D``arr1 ``=` `geek.arange(``5``)``print``(``"1D arr1 : "``, arr1)``print``(``"Shape : "``, arr1.shape)`` ` ` ` `arr2 ``=` `geek.arange(``8``, ``12``)``print``(``"\n1D arr2 : "``, arr2)``print``(``"Shape : "``, arr2.shape)`` ` ` ` `# appending the arrays``arr3 ``=` `geek.append(arr1, arr2)``print``(``"\nAppended arr3 : "``, arr3)`

Output :

```1D arr1 :  [0 1 2 3 4]
Shape :  (5,)

1D arr2 :  [ 8  9 10 11]
Shape :  (4,)

Appended arr3 :  [ 0  1  2  3  4  8  9 10 11]

```

Code 2 : Playing with axis

 `# Python Program illustrating``# numpy.append()`` ` `import` `numpy as geek`` ` `#Working on 1D``arr1 ``=` `geek.arange(``8``).reshape(``2``, ``4``)``print``(``"2D arr1 : \n"``, arr1)``print``(``"Shape : "``, arr1.shape)`` ` ` ` `arr2 ``=` `geek.arange(``8``, ``16``).reshape(``2``, ``4``)``print``(``"\n2D arr2 : \n"``, arr2)``print``(``"Shape : "``, arr2.shape)`` ` ` ` `# appending the arrays``arr3 ``=` `geek.append(arr1, arr2)``print``(``"\nAppended arr3 by flattened : "``, arr3)`` ` `# appending the arrays with axis = 0``arr3 ``=` `geek.append(arr1, arr2, axis ``=` `0``)``print``(``"\nAppended arr3 with axis 0 : \n"``, arr3)`` ` `# appending the arrays with axis = 1``arr3 ``=` `geek.append(arr1, arr2, axis ``=` `1``)``print``(``"\nAppended arr3 with axis 1 : \n"``, arr3)`

Output :

```2D arr1 :
[[0 1 2 3]
[4 5 6 7]]
Shape :  (2, 4)

2D arr2 :
[[ 8  9 10 11]
[12 13 14 15]]
Shape :  (2, 4)

Appended arr3 by flattened :  [ 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15]

Appended arr3 with axis 0 :
[[ 0  1  2  3]
[ 4  5  6  7]
[ 8  9 10 11]
[12 13 14 15]]

Appended arr3 with axis 1 :
[[ 0  1  2  3  8  9 10 11]
[ 4  5  6  7 12 13 14 15]]
```

References :
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.append.html#numpy.append
.
This article is contributed by Mohit Gupta_OMG ðŸ˜€. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.