What does an x = y or z assignment do in Python?

In Python, the expression x = y or z is an example of using the logical or operator in an assignment. This operator evaluates the operands from left to right and returns the first operand that evaluates to True in a boolean context, or the last operand if none are True.

Here's how it works step-by-step:

1. Evaluate y: Python first evaluates the operand y. If y is truthy (i.e., it evaluates to True in a boolean context), then y becomes the value of x.
2. Evaluate z (if necessary): If y is falsy (i.e., it evaluates to False in a boolean context), Python then evaluates z. Regardless of whether z is truthy or falsy, its value is assigned to x because it's the last operand evaluated.

This means that x will be assigned the value of y if y is truthy. If y is falsy, x will be assigned the value of z. This behavior makes x = y or z a useful shorthand for conditional assignments where you want to assign a default value (z) if the primary value (y) is co...