Meaning
Returns the first element of a list.
Primary Function
Retrieve the first element from a list.
Communicative Purpose
Express the operation of accessing the first element of a list in a generic, type‑safe way.
Pattern
def get_first(items: list[T]) -> T: return items[0]
Core Structure
function definition with generic type variable T, parameter items of type list[T], return type T, body returns items[0]
Função primária
Retrieve the first element from a list.
Propósito comunicativo
Express the operation of accessing the first element of a list in a generic, type‑safe way.
Situações de gatilho
When you need the first element of a non‑empty list and want a reusable, typed helper.
Contextos
Utility libraries, data‑processing pipelines, generic algorithms, helper functions.
Padrão
def get_first(items: list[T]) -> T: return items[0]
Estrutura central
function definition with generic type variable T, parameter items of type list[T], return type T, body returns items[0]
Slots de substituição
items: list[T], T: type variable
Colocados típicos
- list
- items
- first
- head
- index 0
Substituições comuns
- items[0]
- next(iter(items))
- itertools.islice(items
- 1)
Erros comuns
Assuming the list is non‑empty and getting an IndexError on empty input; using pop(0) which mutates the list; forgetting to handle the empty case.
Similar / contraste
get_last, get_at, slice
Interferências
Confusing with get_last or using pop(0) which modifies the list; expecting None on empty input.
Família do chunk
- list accessors
- head/tail functions
Nuance
Returns the actual first element but raises IndexError if the list is empty; does not modify the original list.
Efeito pragmático
Signals the intent to retrieve the first element and implies the caller believes the list is non‑empty.
Dica de memória
first item
Nota
Will raise IndexError on an empty list; for a safe fallback use next(iter(items), None).
Upgrade path
get_last or get_at index
Log in to save chunks.