Is there a standardized method to swap two variables in Python?

How does it work?

The magic in this line is tucked within Python's evaluation order. Here's the secret: Python evaluates the right-hand side (RHS) before the left-hand side (LHS). In other words, it first creates a tuple (b, a) and then assigns this tuple's values to the variables on the LHS: a and b.

Mind the memory

There's another advantage to this method: it conserves memory. By utilizing tuple unpacking, Python cleverly avoids the need for an explicit temporary variable. The temp tuple is created behind the scenes, enabling a cleaner and more efficient swap.

For the integer lovers

For swapping plain integers, we can also use the XOR (exclusive or) operation:

a = a ^ b
b = a ^ b  # Wait, what? In Python we trust!
a = a ^ b
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This is another way to swap variables, although only applicable to integers - and arguably less intuitive than the first method.

Under the microscope

Digging into object-labeling in Python

There's an important detail to consider: objects and variables in Python. In a nutshell, variables in Python are more like stickers on objects, rather than containers holding values. So, when we're swapping variables, we're essentially just switching the stickers between objects.

Applying swaps to multi-dimensional arrays

When dealing with multi-dimensional arrays, swapping elements requires us to deal with references and specify the indexes for all dimensions:

array[i][j], array[k][l] = array[k][l], array[i][j]  # Slice, dice, swap, nice!
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However, if you're using NumPy arrays, we have to play by different rules due to how slicing operations work:

import numpy as np  # Bring in the big guns
array[:, [i, j]] = array[:, [j, i]]  # Bet you didn't see that coming!
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Remember to always import NumPy as 'np' for the sake of brevity.

Avoiding common pitfalls

The left, right = right, left swap operation can lead to errors or unintended changes if not used judiciously. Make sure the variables you want to swap do not overlap within the operation's context to prevent any data loss.