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
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