Generate a transformed list via list comprehension.

Express a concise transformation of a range into a list.

When you need to produce a list of transformed values from a range or iterable.

Python list comprehensions, data transformation, functional‑style programming.

[expression for item in iterable]

[expression for item in iterable]

{"expression":"x*2","item":"x","iterable":"range(5)"}

• range list map filter lambda

• {"expression":"any expression involving the item variable"
• "item":"any valid variable name"
• "iterable":"any iterable object"}

forgetting the square brackets (creating a generator expression) misspelling the iteration variable using parentheses instead of brackets using an invalid iterable

map(lambda x: x*2, range(5)) [x*2 for x in range(5) if x%2==0] [x*2 for x in range(5)] == list(map(lambda x: x*2, range()))]

Confusing with generator expression (x*2 for x in range(5)) which yields a generator object Confusing with map() which returns an iterator in Python 3

• list comprehension patterns

Produces a new list; does not modify the original iterable; evaluation is eager.

Conveys a concise, idiomatic way to apply a transformation to a sequence in Python.

Think ‘double each number from zero to four’.

Common idiom for simple transformations; often preferred over map for readability.

Consider generator expressions for memory efficiency or map/filter for functional style.