__getitem__
__getitem__ is a Python special method that defines subscription access to an object's elements using square-bracket notation.
The Quick Python Book, Fourth Edition
__getitem__ is a Python special method that defines how an object responds when an item or slice is accessed with subscription syntax.
- How it is used
- Enables user-defined objects to support indexed access and, in the sequential example, iteration.
- How deep it goes
- Explains subscription dispatch, sequential iteration, and `IndexError` termination, then contrasts narrow iteration with index-aware list behavior.
- Examples
- Uses a line-by-line file reader and a type-checked list backed by a regular list.
- What you can do after
- Build it from scratch: define indexed access for a class and use `IndexError` to end sequential iteration.
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Deep Learning with PyTorch, Second Edition
A Python special method that retrieves an item by index or key, used here by Dataset to return a sample and label.
- How it is used
- Provides indexed access to individual samples for PyTorch Dataset objects used in image classification and custom training or validation datasets.
- How deep it goes
- Defines the index contract and demonstrates sample construction, tensor conversion, dimensions, and multi-value returns without descending into method internals.
- Examples
- Uses CIFAR-10 image access and a LunaDataset tuple containing tensors, a series identifier, and coordinates.
- What you can do after
- Apply it via PyTorch Dataset subclassing to retrieve and format indexed samples for training or validation.
Read how Deep Learning with PyTorch, Second Edition explains __getitem__ →
Related concepts
- datasetimplemented by · A dataset is an organized collection of related data items, records, or observations treated as a unit for storage, processing, analysis, or computation.
- loopused by · A loop is a programming control-flow construct that repeatedly executes a block of instructions according to an iteration rule or continuation condition.
- square bracketsequivalent to · Square brackets are paired punctuation marks used in programming-language syntax to delimit expressions or constructs, including indexing and collection literals.
- iterableimplements · An iterable is an object or value that provides or supports a protocol for producing its elements sequentially.
- special methodkind of · A special method is a Python method with a conventionally reserved name that defines an object's behavior for language operations or built-in functions.
- functionkind of · A function is a callable program unit that performs an operation, may accept inputs, and can produce a result or side effect.
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