I’m taking a python course and there is a question that requires adding a user’s input.

The question is:

Sometimes a programmer does not know how many times data is to be
entered. For example, suppose you want to create a program that adds
an unspecified amount of positive numbers entered by the user. The
program stops adding numbers when the user enters a zero or a negative
number. Then the program prints the total. Before creating this
program, review the three actions required for all loops:

a. Initialize a variable that will be used in the test condition: What
will be tested to determine if the loop is executed or not? Write a
line of code that initializes a variable to be used in the test
condition of the loop for this program. The variable should contain a
value entered by the user.

b. Include a test condition that causes the loop to end when the
condition is false: What is the test condition for the while loop used
in this program?

c. Within the loop body, update the variable used in the test
condition: Write the code for the loop body. Include the code to
update the variable in the test condition.

d. Complete the program. Enter and execute the code. Does it work
properly?

The code I have is:

while True:
  a = int(input("Enter a positive number: "))
  total = a + a
  if a>0:
    a+a

  else:
    print("The number you entered is a negative number or 0 \n The sum is: ", total)
    break

The program doesn’t add all the values the user entered, how do I fix this?