Python always uses pass-by-reference values. There isn't any exception. Any variable assignment means copying the reference value.

Does Python pass by reference or value?

In Python,Values are passed to function by object reference. if object is immutable(not modifiable) than the modified value is not available outside the function. if object is mutable (modifiable) than modified value is available outside the function.

Does Python pass int by reference?

"Python passes objects." No. Python passes references (pointers to objects).