# numpy.alen() in Python

`numpy.alen() `function is used to return the length of the first dimension of the input array.

Syntax : numpy.alen(arr)

Parameters :
arr : [array_like] Input array.

Return : [int]Length of the first dimension of arr.

Code #1 :

 `# Python program explaining ` `# alen() function ` `  `  `import` `numpy as geek ` ` `  `# input array(2 * 3) ` `in_arr ``=` `geek.array([[ ``2``, ``0``, ``7``], [ ``0``, ``5``, ``9``]]) ` `print` `(``"Input array : "``, in_arr)  ` ` `  `out_dim ``=` `geek.alen(in_arr) ` `print` `(``"Length of the first dimension of arr: "``, out_dim) `

Output:

```Input array :  [[2, 0, 7], [0, 5, 9]]
Length of the first dimension of arr:  2
```

Code #2 :

 `# Python program explaining ` `# alen() function ` `  `  `import` `numpy as geek ` ` `  `# input array(1 * 3*3) ` `in_arr ``=` `geek.arange(``9``).reshape(``1``, ``3``, ``3``) ` `print` `(``"Input array : \n"``, in_arr)  ` ` `  `out_dim ``=` `geek.alen(in_arr) ` `print` `(``"Length of the first dimension of arr: "``, out_dim) `

Output:

```Input array :
[[[0 1 2]
[3 4 5]
[6 7 8]]]
Length of the first dimension of arr:  1
```
My Personal Notes arrow_drop_up Check out this Author's contributed articles.

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.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.