How Can I Efficiently Transpose a 2D Matrix in Python?

Matrix Transposition in Python

Matrix transposition involves flipping a matrix's rows and columns to create a new matrix with its original dimensions reversed. Let's consider how to develop a Python function to transpose a 2D matrix.

You provided a Python function, but it does not work correctly. Let's examine your code and identify the errors. In your function:

• You are creating a new transposed matrix with the correct height but an incorrect width. It should be [None] * len(anArray) instead of [None] * len(anArray[0]).
• You are overwriting the values in transposed[t] in each iteration. To create a new column, you need to append the value to the existing list in transposed[t].

Here's a corrected version of your function:

def matrixTranspose(anArray):
    transposed = [[] for _ in range(len(anArray))]
    for t in range(len(anArray)):
        for tt in range(len(anArray[t])):
            transposed[tt].append(anArray[t][tt])
    return transposed

Another concise solution exists using Python's built-in zip function, which combines corresponding elements from multiple iterables. It transposes the matrix by creating tuples from the columns and then converting them back to lists:

transposed = list(zip(*anArray))

For Python 3, prefer using the * operator to unpack the tuples and create a list of lists:

transposed = [*zip(*anArray)]

These methods will efficiently transpose a 2D matrix in Python.

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