function - what is the difference between return and break in python?

Question

what is the difference between return and break in python? Please explain what they exactly do in loops and functions? thank you

Answer 1

break is used to end a loop prematurely while return is the keyword used to pass back a return value to the caller of the function. If it used without an argument it simply ends the function and returns to where the code was executing previously.

There are situations where they can fulfil the same purpose but here are two examples to give you an idea of what they are used for

Using break

Iterating over a list of values and breaking when we've seen the number 3.

def loop3():
    for a in range(0,10):
        print a
        if a == 3:
            # We found a three, let's stop looping
            break
    print "Found 3!"

loop3()

will produce the following output

0
1
2
3
Found 3!

Using return

Here is an example of how return is used to return a value after the function has computed a value based on the incoming parameters:

def sum(a, b):
    return a+b

s = sum(2, 3)
print s

Output:

5

Comparing the two

Now, in the first example, if there was nothing happening after the loop, we could just as well have used return and "jumped out" of the function immediately. Compare the output with the first example when we use return instead of break:

def loop3():
    for a in range(0, 6):
        print a
        if a == 3:
            # We found a three, let's end the function and "go back"
            return

    print "Found 3!"

loop3()

Output

0
1
2
3