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Mastering flat_map in Python with List Comprehension

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Introduction In Python, when working with nested lists or iterables, one common challenge is flattening them into a single list while applying transformations. Many programming languages provide a built-in flatMap function, but Python does not have an explicit flat_map method. However, Python’s powerful list comprehensions offer an elegant way to achieve the same functionality. This article examines implementation behavior using Python’s list comprehensions and other methods. What is flat_map ? Functional programming  flatMap is a combination of map and flatten . It transforms the collection's element and flattens the resulting nested structure into a single sequence. For example, given a list of lists, flat_map applies a function to each sublist and returns a single flattened list. Example in a Functional Programming Language: List(List(1, 2), List(3, 4)).flatMap(x => x.map(_ * 2)) // Output: List(2, 4, 6, 8) Implementing flat_map in Python Using List Comprehension Python’...
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Python Set comprehension - How to Use it Read now

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In python, Set does not allow duplicates, and  you can't modify an existing set with a comprehension. But using the Set comprehension you can create a new Set.


set comprehension


Set Comprehension 


In addition, the comprehension must result in a valid set.  Likewise Dictionary, a set does not allow entries of the same value.


If you try to add values to the set that are already there, it will replace the old one with the new one.

Explained syntax

Set comprehensions using the {} syntax only exist in Python 3. Before that, you'll have to use the set() function to create and work with sets. You might guess, therefore, that one of the best uses of a set is to eliminate duplicates.

In fact, this is one of the most basic forms of set comprehension. Given a list, we can duplicate it as a list with a simple list comprehension like this:

Details of logic

if we change the list comprehension to a set comprehension, we get the same result, but as a set. That means without duplicates.

list_copy = [x for x in original_list]
 

Sample Set comprehension

my_list_with_dupes = [1,2,1,2,3,4,1,2,3,4,5,6,7,1,2,3] 
my_set_without_dupes = {x for x in my_list_with_dupes} 
print(my_set_without_dupes) 

{1, 2, 3, 4, 5, 6, 7}


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