Meaning
Creates a new dictionary with keys and values swapped from the given dictionary.
Primary Function
Inverts a dictionary mapping.
Communicative Purpose
Expresses a dictionary comprehension that swaps keys and values.
Pattern
{v:k for k,v in <iterable>.items()}
Core Structure
{v:k for k,v in <iterable>.items()}
Função primária
Inverts a dictionary mapping.
Propósito comunicativo
Expresses a dictionary comprehension that swaps keys and values.
Situações de gatilho
When you need to reverse a mapping, e.g., to look up keys by their values.
Contextos
Data transformation, building lookup tables, inverting mappings.
Padrão
{v:k for k,v in <iterable>.items()}
Estrutura central
{v:k for k,v in <iterable>.items()}
Slots de substituição
<iterable>: any iterable yielding key‑value pairs (e.g., dict.items(), list of tuples, zip(...))
Colocados típicos
- dict
- items()
- dict comprehension
- zip
- lookup table
Substituições comuns
- Any iterable of pairs
- e.g.
- list of tuples
- zip(*pairs)
Erros comuns
Assuming values are unique; duplicate values cause later keys to overwrite earlier ones.
Similar / contraste
Similar to dict(zip(values, keys)) but more readable; contrasts with the identity comprehension {k:v for k,v in d.items()}.
Interferências
If values are not hashable or are duplicated, information may be lost.
Família do chunk
- dictionary comprehensions
Nuance
Only works when values are hashable and unique; otherwise later keys overwrite earlier ones.
Efeito pragmático
Conveys the idea of inverting a mapping for reverse lookup.
Dica de memória
Think ‘flip the dictionary’.
Nota
Useful for creating reverse lookup dictionaries; beware of non‑unique values.
Upgrade path
Learn basic dict comprehensions, then explore dict constructor with zip and handling duplicate values.
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