“While” and “For” loop in python

< Previous

Next >

Python has two types of loop, “while” and “for” loop.

While loop

It executes statement until condition is true, when condition became false it goes to the out of the loop.

>>> a = 5

>>> while a>0:

print(“the number is”, a)

a--

“break” statement

Use to stop execution as per given condition.

>>> a = 5

>>> while a>0:

if a==4:

break

print(“the number is”, a)

a--

“continue” statement

It uses to return to loop again without executing the next statements.

>>> a = 5

>>> while a>0:

a--

if a==4:

continue

print(“the number is”, a)

It does not print value 4.

For loop

It uses to execute the iterative value of any sequences like – dic, list, sets, etc.

>>> name = [“naveen”, “jitendra”, “sachin”, “arvind”]

>>> for a in name:

print(a)

If you pass a single string then it executes all characters of string because string contains inerrable objects.

>>> string = "codersarts"

>>> for a in string:

print(a)

It displays the result c, o, d, e …

Range() in loop

It executes statements as per given range and it starts from 0 indexes, see in below:

>>> for a in range(5):

print(a)

It print values from 0 to 4 not 0 to 5.

>>> range(2, 5) #use to select range between this range.

>>> range(2, 22, 5) #increment sequence by 5(by default 1)

Loop inside another loop(nested loop)

>>> name = [“naveen”, “jitendra”, “sachin”]

>>> name = [“etah”, “ptna”, “hrdoi”]

for x in name:

for y in address:

print(x, y)

Now it finishes in the next tutorial we will learn "python function" which is also is important

for learning the python loop concept.