fast-protocol 1.0.1

A very simple Python module to declare protocols for checking if objects provide the desired interface.

fast-protocol

A very simple Python module to declare protocols for checking if objects provide the desired interface.

Installation

pip install fast-protocol

Usage

To create a Fast Protocol just call the fast_protocol.protocol function passing it the names of the methods/attributes that the protocol should support.

from fast_protocol import protocol

def example():
    ...

Callable = protocol("__call__")  # Create a protocol that matches objects with a dunder call method
match example:
    case Callable():
        print("example is callable")

This can be used outside a match statement using isinstance.

if isinstance(example, Callable):
    print("example is callable")

Protocols are generated with the name "FastProtocol". This name can be changed by creating a new instance of FastProtocolBuilder. The name can be set traditionally by passing the name of the protocol to the FastProtocolBuilder class. Alternatively you can pass the protocol name as a subscript to an existing FastProtocolBuilder which will return a new instance that uses that name.

Traditional approach:

from fast_protocol import FastProtocolBuilder

Callable = FastProtocolBuilder("Callable")("__call__")

Alternative approach:

from fast_protocol import protocol

Callable = protocol["Callable"]("__call__")