A list comprehension in Python is a concise way to create a new list by iterating over an existing iterable, such as a list, tuple, or string, and applying a condition to each element in the iterable. It is a syntactic construct that allows you to create a new list in a single line of code.
The general syntax of a list comprehension is as follows:
new_list = [expression for item in iterable if condition]
Here, expression is an expression that is evaluated for each item in the iterable, item is a variable that represents each item in the iterable, iterable is the iterable being looped over, and condition is an optional condition that filters the items in the iterable based on a boolean expression.
For example, the following list comprehension creates a new list containing the squares of the first ten integers:
squares = [x**2 for x in range(1, 11)] print(squares) # Output: [1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
In this example, the range() function generates the numbers 1 through 10, and the x**2 expression squares each number in the range.
List comprehensions can also be nested, and can include multiple conditions and expressions. They are a powerful and expressive tool in Python that can make your code more concise and readable.
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