How to make function that calculates moving average of a list?

Question

I am trying to calculate a moving average of a list called 'temp_data' in the function below. The moving average data should be stored in a list called 'moving_average'. The code below works in the sense that list 'temp_mov' is printed inside the function (line 12), but not when I call the function later on (in the last line of the code). In that case, I get an empty list. What mistake do I make?

   # calculate moving average of a list of weather data

    def make_moving(temps, temp_mov):
            ''' Create moving average from list weather data'''

            cumsum, temp_mov = [0], []
            for i, x in enumerate(temps, 1):
                    cumsum.append(cumsum[i-1] + x)
                    if i>=N:
                          moving_ave = round((cumsum[i] - cumsum[i-N])/N, 1)
                          temp_mov.append(moving_ave)
            print(temp_mov) 
            return temp_mov

  make_moving(temp_data, moving_average)
  print(moving_average)

Answer 1

You assign a new list to temp_mov here:

cumsum, temp_mov = [0], []

Therefore, moving_average is not updated when temp_mov changes.

Changing make_moving(temp_data, moving_average) to moving_average = make_moving(temp_data) and removing the temp_mov parameter will solve the problem.