Question

The code that I am working on is changing my temporary variables, and I can’t figure out how to stop it. Essentially, this is the problem:

def example(array):
    temp = array
    for i in range whatever:
        #change array

I need to change array, but keep temp the same.

Answer 1

The line

temp = array

does not copy the contents of array – it simply binds another name to the same object. How to actually copy an object depends on the type of the object. For a NumPy array, you can do

temp = array.copy()

For a Python list, you can use the above line starting from Python 3.3; in eariler version, you can use

temp = array[:]

There are also the generic copying functions copy() and deepcopy() in the module copy.