Course Content
Python Loops Tutorial
Python Loops Tutorial
The First For Loop
Using loops you can iterate over sequences like lists
, strings
, or numerical ranges
, they allow to process large amounts of data with minimal code.
py
item
is a variable that takes the value of each element in the sequence one at a time;sequence
is the data you are iterating through, such as a list, string, or range;for
statement block is executed for everyitem
in the sequence.
Imagine you have a string variable and want to print each letter of it in a column. Since a string is a sequence of letters, you can use a loop to achieve this.
word = 'iteration' letters = [] # Adding every letter in the word to the list for letter in word: letters.append(letter)
- The
word
variable holds the string'iteration'
. - The
for
loop iterates over each character in the string. - Each character is appended to the
letters
list in each iteration. - After the loop,
letters
contains all the characters from'iteration'
as individual elements.
Make sure to name the item
variable meaningfully. For example, if you iterate through a list called people
, the appropriate variable name should be person
.
Swipe to start coding
You are a traveler who wants to create a travel list. You have a list of countries and need to add them to your travel list.
- Iterate through the
countries
list using afor
loop. - Update
travel_list
so that it contains only the countries fromcountries
.
Solution
Thanks for your feedback!
The First For Loop
Using loops you can iterate over sequences like lists
, strings
, or numerical ranges
, they allow to process large amounts of data with minimal code.
py
item
is a variable that takes the value of each element in the sequence one at a time;sequence
is the data you are iterating through, such as a list, string, or range;for
statement block is executed for everyitem
in the sequence.
Imagine you have a string variable and want to print each letter of it in a column. Since a string is a sequence of letters, you can use a loop to achieve this.
word = 'iteration' letters = [] # Adding every letter in the word to the list for letter in word: letters.append(letter)
- The
word
variable holds the string'iteration'
. - The
for
loop iterates over each character in the string. - Each character is appended to the
letters
list in each iteration. - After the loop,
letters
contains all the characters from'iteration'
as individual elements.
Make sure to name the item
variable meaningfully. For example, if you iterate through a list called people
, the appropriate variable name should be person
.
Swipe to start coding
You are a traveler who wants to create a travel list. You have a list of countries and need to add them to your travel list.
- Iterate through the
countries
list using afor
loop. - Update
travel_list
so that it contains only the countries fromcountries
.
Solution
Thanks for your feedback!