How to convert singleton array to a scalar value in Python?

Question

Suppose I have 1x1x1x1x... array and wish to convert it to scalar?

How do I do it?

squeeze does not help.

import numpy as np

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Answer 1

>>> float(np.array([[[[1]]]]))
1.

Answer 2

You can use the item() function:

import numpy as np

matrix = np.array([[[[7]]]])
print(matrix.item())

Output

7

Answer 3

You can index with the empty tuple after squeezing:

x = np.array([[[1]]])
s = np.squeeze(x)  # or s = x.reshape(())
val = s[()]
print val, type(val)

Answer 4

Numpy has a function explicitly for this purpose: asscalar

>>> np.asscalar(np.array([24]))
24

This uses item() in the implementation.

I guess asscalar was added to more explicit about what's going on.

Answer 5

You can use np.take -

np.take(matrix,0)

Sample run -

In [15]: matrix = np.array([[67]])

In [16]: np.take(matrix,0)
Out[16]: 67

In [17]: type(np.take(matrix,0))
Out[17]: numpy.int64