Can I replace while loop with range function. I am using following code
check = 0
while check<5:
print check
check+=2
I am writing in following way
for _check in range(0,5,2):
print _check
is it correct way?
> Editing My question
if I am not using _check variable inside for loop. Can I avoid to declare also
Yes, you are using range() correctly, but you may want to use xrange() instead here:
for check in xrange(0, 5, 2):
print check
xrange() produces the same results when iterated over, but doesn't build a whole list of all possible indices first, and as a result uses less memory:
>>> range(0, 5, 2)
[0, 2, 4]
>>> xrange(0, 5, 2)
xrange(0, 6, 2)
Since the end-point is not included in the values, it doesn't matter if you use 5 or 6 here as the endpoint, it is just calculated for you from the input parameters.
If you are not using the loop variable, you can use _ to indicate that you are ignoring it in the loop. This is just a naming convention:
for _ in xrange(0, 5, 2):
# do something 3 times.
in which case you may as well just calculate how many indices there are between 0 and 5 with a step of two and simplify your loop to:
upper_limit, step = 5, 2
for _ in xrange((upper_limit - 1 + step) // step):
# do something 3 times.
Regarding the original while loop, using check = check + 1
for x in xrange(5):
print x
See the documentation here for more information on control flow tools (like loops).
EDIT
If you want to increment by 2 during each iteration, you can use the above code with the increment specified:
for x in xrange(0,5,2):
print x
while loop to increment in steps of two. Or was there a grace-period edit that changed the check + 1 into a check + 2?