flytekit.core.hash

Directory

Classes

flytekit.core.hash.Generic

Abstract base class for generic types.

On Python 3.12 and newer, generic classes implicitly inherit from Generic when they declare a parameter list after the class’s name::

class Mapping[KT, VT]: def getitem(self, key: KT) -> VT: …

Etc.

On older versions of Python, however, generic classes have to explicitly inherit from Generic.

After a class has been declared to be generic, it can then be used as follows::

def lookup_name[KT, VT](mapping: Mapping[KT, VT], key: KT, default: VT) -> VT: try: return mapping[key] except KeyError: return default

flytekit.core.hash.HashMethod

Flyte-specific object used to wrap the hash function for a specific type

def HashMethod(
    function: typing.Callable[[~T], str],
):

Methods

calculate()

def calculate(
    obj: ~T,
):

Calculate hash for obj.

flytekit.core.hash.HashOnReferenceMixin

flytekit.core.hash.TypeVar

Type variable.

The preferred way to construct a type variable is via the dedicated syntax for generic functions, classes, and type aliases::

class Sequence[T]: # T is a TypeVar …

This syntax can also be used to create bound and constrained type variables::

S is a TypeVar bound to str

class StrSequence[S: str]: …

A is a TypeVar constrained to str or bytes

class StrOrBytesSequence[A: (str, bytes)]: …

However, if desired, reusable type variables can also be constructed manually, like so::

T = TypeVar(‘T’) # Can be anything S = TypeVar(‘S’, bound=str) # Can be any subtype of str A = TypeVar(‘A’, str, bytes) # Must be exactly str or bytes

Type variables exist primarily for the benefit of static type checkers. They serve as the parameters for generic types as well as for generic function and type alias definitions.

The variance of type variables is inferred by type checkers when they are created through the type parameter syntax and when infer_variance=True is passed. Manually created type variables may be explicitly marked covariant or contravariant by passing covariant=True or contravariant=True. By default, manually created type variables are invariant. See PEP 484 and PEP 695 for more details.