for Loop

When you need to loop through a specific set of values, the for loop is your go-to in Python. Unlike some other languages, you don't need a predefined counter variable for this loop. Instead, you use an iterator variable, which you don't have to define ahead of time. Python for loops can work with sequence types, including lists, tuples, strings, and dictionaries. For instance, if you loop through a string:


              123456
            
# Initial string
word = 'Codefinity'

# Initialize a for loop
for i in word:
  print(i, end = ' ')

Note

In this code, i is a variable that takes on the value of each character in the string word during each iteration of the for loop. As the loop progresses, i sequentially represents each character in 'Codefinity', and each character is printed out.

As shown, the loop runs through each character (or element) of the string. Similarly, when looping through a list, it covers every item in that list.


              123456
            
# Initial list
values = [1, [2, 3], 4, "code"]

# Initialize a for loop
for el in values:
  print(el, end = ' ')

Note

The for loop doesn't need you to set up a counter variable in advance. You're free to pick any variable name that suits you. Many programmers gravitate towards names like i or j. In our second example, we opted for el, short for 'element'.

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Section 5. Chapter 3