We can use the for
loop in the following ways:
>>> food = ['ham', 'egg', 'spam'] >>> for snack in food: ... print(snack) ... ham egg spam
range()
or xrange()
functions. The latter function is slightly more efficient in certain cases. Loop over the numbers 1-9
with a step of 2 as follows:>>> for i in range(1, 9, 2): ... print(i) ... 1 3 5 7
range()
function are optional with default values of 1
. We can also prematurely end a loop. Loop over the numbers 0-9
and break out of the loop when you reach 3
:>>> for i in range(9): ... print(i) ... if i == 3: ... print('Three') ... break ... 0 1 2 3 Three
3
and we did not print the higher numbers. Instead of leaving the loop, we can also get out of the current iteration. Print the numbers 0-4
, skipping 3
as follows:>>> for i in range(5): ... if i == 3: ... print('Three') ... continue ... print(i) ... 0 1 2 Three 4
3
because of the continue
statement. In Python, the for
loop can have an else
statement attached to it. Add an else
clause as follows:>>> for i in range(5): ... print(i) ... else: ... print(i, 'in else clause') ... 0 1 2 3 4 (4, 'in else clause')
else
clause last. Python also has a while
loop. I do not use it that much because the for
loop is more useful in my opinion.