Python Loops

Python For Loops

In computer science, a for-loop (or simply for loop) is a control flow statement for specifying iteration, which allows code to be executed repeatedly. ... For-loops are typically used when the number of iterations is known before entering the loop.

Task:

  • Copy the example below into python then.....
  • See if you can work out what each line of code is doing.
  • Add #comments to explain the code.
  • Now see if you can create your own for loop to run through a list of your favourite songs.

 

#for loop example
#remember list positions start at 0!
animals=["cat","mouse","chimp","pig","dog","cow"]

for i in animals:
    print("first animal index position:",animals.index(i))
    print("first animal name:",i)
print("Finished")

 

Python While loops

In computer programming languages, a while loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop can be thought of as a repeating if statement.

Task:

  • Copy the example below into python then.....
  • See if you can work out what each line of code is doing.
  • Add #comments to explain the code.
  • Now see if you can create your own while loop to count down from 100 to 0.
  • Print 'Blast off' when your count down reaches zero.
  • Write import time at the top of your code and use time.sleep(1)  to slow down your count.

 

#while loop example
count=0
while count <= 100:
    print("Number:",count)
    count+=1
print("End of count")

 

 

Next

Check out the python challenges pages to see more complex examples of loops.