Represents a collection of records where each record maps string keys to lists of integer values.

Describes a data structure for grouping integer lists by string keys, useful for categorizing numeric data.

When you need to store multiple integer lists labeled by string identifiers, e.g., grouping time series by category or mapping labels to sequences of integer scores.

Data processing, scientific data aggregation, machine learning feature grouping, configuration mapping.

List[Dict[str, List[int]]]

List of dictionaries mapping string keys to lists of integers

List[Dict[str, List<T>]] where T is int

• data
• records
• mapping
• groups
• categories

• List[Dict[str
• List[float]]]
• Dict[str
• List[List[int]]]

Confusing List[Dict[str, List[int]]] with Dict[str, List[List[int]]]; mixing up key and value types.

Similar: List[Tuple[str, List[int]]]; Contrasting: Dict[str, int] or List[List[int]]

Confusing the order of type parameters; mistaking List[Dict[str, List[int]]] for List[List[Dict[str, int]]].

• List[Dict[str
• int]]
• List[List[int]]
• Dict[str
• List[int]]

The outer list indicates multiple records; each dictionary may have varying keys; inner lists may vary in length.

Communicates a structured, typed collection of grouped integer data.

Think of a list of dictionaries where each key points to a list of integers.

Commonly used in type annotations for configuration or intermediate data structures.

List[Dict[str, List[float]]]