# NumPy | Create array filled with all ones

Last Updated : 09 Feb, 2024

To create an array filled with all ones, given the shape and type of array we can use numpy.ones() method of NumPy library in Python.

## Python3

 `import` `numpy as np ` ` `  `array ``=` `np.ones(``5``) ` `print``(array)`

Output:

`[1. 1. 1. 1. 1.]`

## Syntax

Syntax: np.ones(shape, dtype=None, order=’C’, *, like=None)

Parameters:

• shape : integer or sequence of integers
• order :
• C_contiguous or F_contiguous
• C-contiguous order in memory(last index varies the fastest)
• C order means that operating row-rise on the array will be slightly quicker
• FORTRAN-contiguous order in memory (first index varies the fastest).
• F order means that column-wise operations will be faster.
• dtype : [optional, float(byDefault)] Data type of returned array.
• like: [optional] allows you to create an array with the same shape and data type as another array-like object

## More Examples

Let’s look at more example on how to create array with all ones with NumPy:

## Python3

 `# Python Program to create array with all ones ` `import` `numpy as geek  ` ` `  `a ``=` `geek.ones(``3``, dtype ``=` `int``)  ` `print``(``"Matrix a : \n"``, a)  ` ` `  `b ``=` `geek.ones([``3``, ``3``], dtype ``=` `int``)  ` `print``(``"\nMatrix b : \n"``, b)  `

Output:

```Matrix a :
[1 1 1]
Matrix b :
[[1 1 1]
[1 1 1]
[1 1 1]]
```

## Python3

 `# Python Program to create array with all ones ` `import` `numpy as geek  ` ` `  `c ``=` `geek.ones([``5``, ``3``])  ` `print``(``"\nMatrix c : \n"``, c)  ` ` `  `d ``=` `geek.ones([``5``, ``2``], dtype ``=` `float``)  ` `print``(``"\nMatrix d : \n"``, d)  `

Output:

```Matrix c :
[[ 1.  1.  1.]
[ 1.  1.  1.]
[ 1.  1.  1.]
[ 1.  1.  1.]
[ 1.  1.  1.]]
Matrix d :
[[ 1.  1.]
[ 1.  1.]
[ 1.  1.]
[ 1.  1.]
[ 1.  1.]]
```

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