NumPy ones()

The `ones()` method creates a new array of given shape and type, filled with ones.

``````import numpy as np

# create an array of 1s
array1 = np.ones(5)

print(array1)

# Output: [1. 1. 1. 1. 1.]``````

ones() Syntax

The syntax of `ones()` is:

``numpy.ones(shape, dtype = None, order = 'C')``

ones() Arguments

The `ones()` method takes three arguments:

• `shape` - desired new shape of the array (can be integer or tuple of integers)
• `dtype` (optional) - datatype of the returned array
• `order` (optional) - specifies the order in which the ones are filled

ones() Return Value

The `ones()` method returns the array of given shape, order, and datatype filled with 1s.

Example 1: Create Array With ones

``````import numpy as np

# create a float array of 1s
array1 = np.ones(5)
print('Float Array: ',array1)

# create an int array of 1s
array2 = np.ones(5, dtype = int)
print('Int Array: ',array2)``````

Output

```Float Array:  [1. 1. 1. 1. 1.]
Int Array:  [1 1 1 1 1]```

If unspecified, the default `dtype` is float.

Example 2: Create nd-Array With ones

``````import numpy as np

# create a n-d array of 1s
array1 = np.ones([2,3])
print('n-d array:\n',array1)``````

Output

```n-d array:
[[1. 1. 1.]
[1. 1. 1.]]```