Python:NumPy .reshape()

The .reshape() method rearranges the data in an ndarray into a new shape. The new shape must be compatible with the old one, though an index of -1 can be used to infer one dimension.

Syntax

ndarray.reshape(newshape)

Where newshape can be an integer or a tuple representing the size of the new array. If a dimension is -1, that dimension will be inferred from the size of the original array.

Unlike the built-in NumPy function .reshape(), dimensions for this method can also be passed as separate arguments: i.e. array.reshape(2,3) is the same as array.reshape((2,3)).

If possible, the ndarray returned will be a view of the original ndarray‘s data.

Example

The following example creates an ndarray then uses .reshape() to change its dimensions.

import numpy as np

nd1 = np.array([[1,2,3],[4,5,6]])

print(nd1)
print(nd1.reshape(3,2))
print(nd1.reshape((-1,1)))

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This produces the following output:

[[1 2 3]
 [4 5 6]]

[[1 2]
 [3 4]
 [5 6]]

[[1]
 [2]
 [3]
 [4]
 [5]
 [6]]

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Codebyte Example

Run the following codebyte example to understand the usage of the .reshape() method:

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