Meaning
Creates a new list by multiplying each element in the input iterable 'numbers' by 2.
Primary Function
Produces a new list where each element is doubled.
Communicative Purpose
Expresses a concise transformation of a collection via list comprehension.
Pattern
[x * 2 for x in iterable]
Core Structure
[expression for item in iterable]
Função primária
Produces a new list where each element is doubled.
Propósito comunicativo
Expresses a concise transformation of a collection via list comprehension.
Situações de gatilho
When you need to transform each element of a collection by applying a uniform operation (e.g., scaling).
Contextos
Used in data processing loops, numerical transformations, functional-style Python code.
Padrão
[x * 2 for x in iterable]
Estrutura central
[expression for item in iterable]
Slots de substituição
x: variable representing each element; numbers: iterable of numbers; 2: multiplier expression (can be any expression).
Colocados típicos
- numbers
- data
- items
- values
Substituições comuns
- x*2 can be replaced with any expression like x+1
- x*len
- func(x).
Erros comuns
Using assignment instead of expression, forgetting brackets, using wrong variable name, unintentionally modifying original list.
Similar / contraste
map(lambda x: x*2, numbers), [x for x in numbers], [x*2 for x in numbers if x>0]
Interferências
Confusing with generator expression (x*2 for x in numbers) which yields a generator, not a list.
Família do chunk
- list comprehension
- map
- filter
- generator expression
Nuance
Produces a new list; does not modify the original iterable.
Efeito pragmático
Conveys intent to transform data succinctly, idiomatic Python.
Dica de memória
double each number
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