How do i use the for loop in python?

petulia3478

For loops in python are like many other scripting & programming languages.

You can loop through (iterate) lists, dictionaries, tuples, and strings and perform various actions on them.

for loops

Here's an example of loop over a list of cakes.

mycakes = ["victoria", "ginger", "carrot"]
for cake in mycakes:
    print("I got " + cake + " cakes!")

I got victoria cakes!
I got ginger cakes!
I got carrot cakes!

You can also use the built-in function called range in for loop for repeating things a number of times. Note that the numbers do not include number 10.

for num in range(1,10):
     print("Hello World, I'm number " + str(num))

Hello World, I'm number 1
Hello World, I'm number 2
Hello World, I'm number 3
Hello World, I'm number 4
Hello World, I'm number 5
Hello World, I'm number 6
Hello World, I'm number 7
Hello World, I'm number 8
Hello World, I'm number 9

It is important where you place your indentations For example the following two give different results.

total  = 0
prices = [2, 4, 6]
for i in prices:
    total += i
print(total)

The result is:

$ ./main.py
12

Where as the following code: The print function become part of the for loop.

total  = 0
prices = [2, 4, 6]
for i in prices:
    total += i
    print(total)

The result is:

$ ./main.py
2
6
12