for loop in python

  • Sometimes we want to loop through a set of things such as a list of words, the lines in a file, or a list of numbers.
  • When we have a list of things to loop through, we can construct a definite loop using a for statement.
  • We call the while statement an indefinite loop because it simply loops until some condition becomes False, whereas the for loop is looping through a known set of items so it runs through as many iterations as there are items in the set.
  • The for loop is a generic iterator in python, it can step through the items in any ordered sequence or other iterable object.
  • Python implements an iterator-based ‘for loop’. It is a type of ‘for loop’ that iterates over a list of items through an explicit or implicit iterator.
  • The loop is introduced by the keyword ‘for’ which is followed by a random variable name which will contain the values supplied by the object.
  • The Python for loop begins with a header line that specifies an assignment target, along with the object you want to step through.


The syntax of a for loop is similar to the while loop in that there is a for statement and a loop body:

    friends = ['Amit', 'Aman', 'Anu']
    for friend in friends:
        print('Happy New Year:', friend)


  • In Python terms, the variable friends is a list of three strings and the for loop goes through the list and executes the body once for each of the three strings in the list resulting in this output:
  • Happy New Year: Amit
    Happy New Year: Aman
    Happy New Year: Anu

Flow Diagram

     for loop in python language