python-dependency-injector/examples/providers/callable.py

"""`Callable` providers examples."""

from objects.providers import Callable
from objects.injections import KwArg


class SomeCrypt(object):

    """Example class SomeCrypt."""

    @staticmethod
    def encrypt(data, password):
        """Encypt data using password."""
        return ''.join((password, data, password))

    @staticmethod
    def decrypt(data, password):
        """Decrypt data using password."""
        return data[len(password):-len(password)]


# Encrypt and decrypt function providers:
encrypt = Callable(SomeCrypt.encrypt,
                   KwArg('password', 'secret123'))
decrypt = Callable(SomeCrypt.decrypt,
                   KwArg('password', 'secret123'))

# Making some asserts:
initial_data = 'some_data'

encrypted1 = encrypt(initial_data)
decrypted1 = decrypt(encrypted1)

assert decrypted1 == initial_data

# Context keyword arguments priority example:
encrypted2 = encrypt(initial_data, password='another_secret')
decrypted2 = decrypt(encrypted2)

assert decrypted2 != initial_data