How to loop through a set using a for loop in Python
Overview
In Python, a set is used to store unordered and unchangeable multiple items in a single variable.
In a code, sets are defined by values between braces { }.
Defining a set
countries = {"USA", "CHINA", "TURKEY"}
In the above example, we see that countries is a set variable whereas "USA", "CHINA", and "TURKEY" are the elements of the set.
Looping through a set in Python
To loop through a set in Python means to repeat something multiple times in the elements of the set. The loop runs until a particular condition is satisfied.
We can loop through a set in Python using a for loop.
Syntax
for (expression):
statement(s)
The expression given in the code above is conventionaly a condition. The statement will execute when the condition given is True.
Example 1
In the below code, we print all the items in the set one by one.
# creating a setcountries = {"USA", "CHINA", "TURKEY"}# using a for loopfor element in countries:print(element)
Explanation
- Line 2: We create a set,
countries. - Line 5: We use a
forloop to create an expression. This makesxbecome each element of the set. - Line 6: We print all the elements of the set.
We use an index variable and call the len() function to iterate over a set. In order to do this, we’ll have to first convert the set to a list object in order to iterate over the items.
Example 2
# creating a setcountries = {"USA", "CHINA", "TURKEY"}# converting the set to a listmylist = list(countries)# using the index value and calling the len() functionfor index in range(len(mylist)):print(mylist[index])
Explanation
- Line 2: We create a set,
countries. - Line 5: We use the
list()function to convert the set variable to a list variable,mylist. This allows us to iterate over items. - Line 8 and 9: We use the index and call the
len()function. Next, we iterate over the items and print them.
