Yield vs Return

In Python, yield and return are both keywords used to send values out of a function, but they do it in very different ways.

return: When you use return in a function, it sends a value back and immediately stops the function. You can’t go back and “pick up where you left off” in that function. It’s like finishing a task and saying, “Here is the result, I’m done!”

def get_number():
   return 5
 
print(get_number())  # Outputs: 5

yield: When you use yield in a function, it sends a value out but pauses the function, allowing it to be resumed later. This turns the function into a generator, meaning you can call it repeatedly to get values one at a time. It’s like a “pause button” that you can resume, picking up from where it last left off each time.

def count_up_to_three():
   yield 1
   yield 2
   yield 3
 
for number in count_up_to_three():
   print(number)  # Outputs: 1, then 2, then 3, one at a time

When to use which:

Use return when you want to send back one final result and stop the function.
Use yield when you want to produce a series of values, one at a time, without losing the function’s current state. This is common when working with large datasets or when the next value depends on the previous ones.