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Python Set Operations Explained: From Theory to Real-Time Applications

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A  set  in Python is an unordered collection of unique elements. It is useful when storing distinct values and performing operations like union, intersection, or difference. Real-Time Example: Removing Duplicate Customer Emails in a Marketing Campaign Imagine you are working on an email marketing campaign for your company. You have a list of customer emails, but some are duplicated. Using a set , you can remove duplicates efficiently before sending emails. Code Example: # List of customer emails (some duplicates) customer_emails = [ "alice@example.com" , "bob@example.com" , "charlie@example.com" , "alice@example.com" , "david@example.com" , "bob@example.com" ] # Convert list to a set to remove duplicates unique_emails = set (customer_emails) # Convert back to a list (if needed) unique_email_list = list (unique_emails) # Print the unique emails print ( "Unique customer emails:" , unique_email_list) Ou...
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Python placeholder '_' Perfect Way to Use it

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What is placeholder in Python? The purpose of it is to mask the variable that you don't want to use in a function. In python, you can call the underscore ( _ ) operator placeholder. Below, you'll find how to use single and double placeholders in a function.


Python placeholder


What is placeholder in python

The purpose of placeholder in Python is to mask variables that you don't want to use in a function. So that your code will be readable. Moreover, in future, if you want to use those variables you can replace the placeholders with the names you want.

In This Page

You'll know in three steps how to use placeholder correctly.
  1. Creating a function
  2. Logic to use single placeholder
  3. Logic to use two placeholders

1. Creating a function.


def function_that_returns_multiple_values(x): 
      return x*2, x*3, x+1 
      for i in range(0,5): 
           square, cube, added_one = function_that_returns_multiple_values(i) 
           print(square, cube)

Here, in print, it returns two variables. I will show you how to mask the unused third variable [added_one] in the below example.

2. Logic to use single placeholder


def function_that_returns_multiple_values(x): 
      return x*2, x*3, x+1 
      for i in range(0,5): 
            square, cube, _ = function_that_returns_multiple_values(i) 
            print(square, cube)

3. Logic to use two placeholders

for i in range(0,5): 
     square, _, _ = function_that_returns_multiple_values(i)


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