How to Extract the First Item from Each Sublist in a Nested Python List?

Extracting First Items from Nested Lists in Python

Given a list of lists, the task is to extract the first item from each sublist and create a new list containing those values. For instance, with a list like [[a,b,c], [1,2,3], [x,y,z]], the desired output would be [a, 1, x].

Solution Using List Comprehension:

A straightforward approach involves using list comprehension:

lst = [['a', 'b', 'c'], [1, 2, 3], ['x', 'y', 'z']]
lst2 = [item[0] for item in lst]

This comprehension iterates over each sublist in lst and selects the first item using the item[0] expression. The extracted values are then appended to the new list, lst2.

Example:

Consider the following example:

lst = [['a', 'b', 'c'], [1, 2, 3], ['x', 'y', 'z']]

# Extract first items of sublists
lst2 = [item[0] for item in lst]

# Print the extracted values
print(lst2)

Output:

['a', 1, 'x']

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