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# Python Language Reference Coverage

This is a 1:1 mapping of the features listed in https://docs.python.org/3/reference/ and their support in TorchScript. The categorizations are as follows:

Section | Status | Note
--- | --- | ---
1. Introduction | Not Relevant |
1.1. Alternate Implementations | Not Relevant |
1.2. Notation | Not Relevant |
2. Lexical analysis | Not Relevant |
2.1. Line structure | Not Relevant |
2.1.1. Logical lines | Not Relevant |
2.1.2. Physical lines | Supported |
2.1.3. Comments | Supported |
2.1.4. Encoding declarations | Not Supported | TorchScript explicitly don’t support unicode
2.1.5. Explicit line joining | Supported |
2.1.6. Implicit line joining | Supported |
2.1.7. Blank lines | Supported |
2.1.8. Indentation | Supported |
2.1.9. Whitespace between tokens | Not Relevant |
2.2. Other tokens | Not Relevant |
2.3. Identifiers and keywords | Supported |
2.3.1. Keywords | Supported |
2.3.2. Reserved classes of identifiers | Supported |
2.4. Literals | Not Relevant |
2.4.1. String and Bytes literals | Supported |
2.4.2. String literal concatenation | Supported |
2.4.3. Formatted string literals | Partially Supported |
2.4.4. Numeric literals | Supported |
2.4.5. Integer literals | Supported |
2.4.6. Floating point literals | Supported |
2.4.7. Imaginary literals | Not Supported |
2.5. Operators | Partially Supported | Not supported: `<<`, `>>`, `:=`
2.6. Delimiters | Partially Supported | Not supported: `**=`, `<<=`, `>>=`, `%=`, `^=`, `@=`, `&=`, `//=`, `%` operator for some types (e.g. `str`)
3. Data model | Not Relevant |
3.1. Objects, values and types | Not Relevant |
3.2. The standard type hierarchy | Partially Supported | Not supported: NotImplemented, Ellipsis, numbers.Complex, bytes, byte arrays, sets, frozen sets, generators, coroutines, async generators, modules, I/O objects, internal objects, slice objects ( though slicing is supported), classmethod
3.3. Special method names | Supported |
3.3.1. Basic customization | Partially Supported | Not supported: `__new__` , `__del__` , `__bytes__` , `__format__` , `__hash__` ,
3.3.2. Customizing attribute access | Not Supported |
3.3.2.1. Customizing module attribute access | Not Supported |
3.3.2.2. Implementing Descriptors | Not Supported |
3.3.2.3. Invoking Descriptors | Not Supported |
3.3.2.4. __slots__ | Not Supported |
3.3.2.4.1. Notes on using __slots__ | Not Supported |
3.3.3. Customizing class creation | Not Supported |
3.3.3.1. Metaclasses | Not Supported |
3.3.3.2. Resolving MRO entries | Not Supported | `super()` is not supported
3.3.3.3. Determining the appropriate metaclass | Not relevant |
3.3.3.4. Preparing the class namespace | Not relevant |
3.3.3.5. Executing the class body | Not relevant |
3.3.3.6. Creating the class object | Not relevant |
3.3.3.7. Uses for metaclasses | Not relevant |
3.3.4. Customizing instance and subclass checks | Not Supported |
3.3.5. Emulating generic types | Not Supported |
3.3.6. Emulating callable objects | Supported |
3.3.7. Emulating container types | Partially Supported | Some magic methods not supported (e.g. `__iter__` )
3.3.8. Emulating numeric types | Partially Supported | Magic methods with swapped operands not supported (`__r*__`)
3.3.9. With Statement Context Managers | Not Supported |
3.3.10. Special method lookup | Not relevant |
3.4. Coroutines | Not Supported |
3.4.1. Awaitable Objects | Not Supported |
3.4.2. Coroutine Objects | Not Supported |
3.4.3. Asynchronous Iterators | Not Supported |
3.4.4. Asynchronous Context Managers | Not Supported |
4. Execution model | Not Relevant |
4.1. Structure of a program | Not Relevant |
4.2. Naming and binding | Not Relevant | Names are bound at compile time in TorchScript
4.2.1. Binding of names | Not Relevant | See `global` and `nonlocal` statements section
4.2.2. Resolution of names | Not Relevant | See `global` and `nonlocal` statements section
4.2.3. Builtins and restricted execution | Not Relevant |
4.2.4. Interaction with dynamic features | Not Supported | Python values cannot be captured
4.3. Exceptions | Partially Supported | See `try` and `raise` statement section
5. The import system | Not Relevant |
6. Expressions | Not Relevant | See expressions section
6.1. Arithmetic conversions | Supported |
6.2. Atoms | Not Relevant |
6.2.1. Identifiers (Names) | Supported |
6.2.2. Literals | Partially Supported | `bytesliteral`, `imagnumber` not supported
6.2.3. Parenthesized forms | Supported |
6.2.4. Displays for lists, sets and dictionaries | Partially Supported | Not supported: comprehension ifs, async iterators
6.2.5. List displays | Supported |
6.2.6. Set displays | Not Supported |
6.2.7. Dictionary displays | Supported | dict() constructor with kwargs doesn’t work, dict comprehensions, dictionary unpacking
6.2.8. Generator expressions | Not Supported |
6.2.9. Yield expressions | Not Supported |
6.2.9.1. Generator-iterator methods | Not Supported |
6.2.9.2. Examples | Not Supported |
6.2.9.3. Asynchronous generator functions | Not Supported |
6.2.9.4. Asynchronous generator-iterator methods | Not Supported |
6.3. Primaries | Supported |
6.3.1. Attribute references | Supported |
6.3.2. Subscriptions | Supported |
6.3.3. Slicings | Partially Supported | Tuple slicing with stride is not supported
6.3.4. Calls | Partially Supported | Args unpack / kwargs unpack is not supported
6.4. Await expression | Not Supported |
6.5. The power operator | Supported |
6.6. Unary arithmetic and bitwise operations | Partially Supported | Some bitwise operators are not implemented for primitive types (e.g. `~x` where `x` is an `int` is not currently supported)
6.7. Binary arithmetic operations | Partially Supported | See delimiters section
6.8. Shifting operations | Not Supported |
6.9. Binary bitwise operations | Supported |
6.10. Comparisons | Supported |
6.10.1. Value comparisons | Partially Supported | Dictionary equality checks are not currently supported
6.10.2. Membership test operations | Partially Supported | Not supported for TorchScript classes
6.10.3. Identity comparisons | Supported |
6.11. Boolean operations | Supported |
6.12. Conditional expressions | Supported |
6.13. Lambdas | Not Supported |
6.14. Expression lists | Partially Supported | Iterable unpacking not supported
6.15. Evaluation order | Supported |
6.16. Operator precedence | Supported |
7. Simple statements | Supported |
7.1. Expression statements | Supported |
7.2. Assignment statements | Supported |
7.2.1. Augmented assignment statements | Partially Supported | See delimiters section
7.2.2. Annotated assignment statements | Supported |
7.3. The assert statement | Partially Supported | Exception message is not customizable
7.4. The pass statement | Supported |
7.5. The del statement | Not Supported |
7.6. The return statement | Supported | Some other features of returning (e.g. behavior with try..finally) are unsupported
7.7. The yield statement | Not Supported |
7.8. The raise statement | Partially Supported | Exception message is not customizable
7.9. The break statement | Supported | Some other features of returning (e.g. behavior with try..finally) are unsupported
7.10. The continue statement | Supported | Some other features of returning (e.g. behavior with try..finally) are unsupported
7.11. The import statement | Not Supported |
7.11.1. Future statements | Not Supported |
7.12. The global statement | Not Supported |
7.13. The nonlocal statement | Not Supported |
8. Compound statements | Irrelevant |
8.1. The if statement | Supported |
8.2. The while statement | Partially Supported | while..else is not supported
8.3. The for statement | Partially Supported | for..else is not supported
8.4. The try statement | Not Supported |
8.5. The with statement | Partially Supported | `__exit__` is always called with `exc_type`, `exc_value`, and `traceback` set to None, even if an exception was raised, and `__exit__`’s return value is ignored.
8.6. Function definitions | Not Supported |
8.7. Class definitions | Not Supported |
8.8. Coroutines | Not Supported |
8.8.1. Coroutine function definition | Not Supported |
8.8.2. The async for statement | Not Supported |
8.8.3. The async with statement | Not Supported |
9. Top-level components | Not Relevant |
9.1. Complete Python programs | Not Relevant |
9.2. File input | Not Relevant |
9.3. Interactive input | Not Relevant |
9.4. Expression input | Not Relevant |

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