Skip to main content

Python Example

"""
Adapter Design Pattern

Intent: Provides a unified interface that allows objects with incompatible
interfaces to collaborate.
"""


class Target:
"""
The Target defines the domain-specific interface used by the client code.
"""

def request(self) -> str:
return "Target: The default target's behavior."


class Adaptee:
"""
The Adaptee contains some useful behavior, but its interface is incompatible
with the existing client code. The Adaptee needs some adaptation before the
client code can use it.
"""

def specific_request(self) -> str:
return ".eetpadA eht fo roivaheb laicepS"


class Adapter(Target, Adaptee):
"""
The Adapter makes the Adaptee's interface compatible with the Target's
interface via multiple inheritance.
"""

def request(self) -> str:
return f"Adapter: (TRANSLATED) {self.specific_request()[::-1]}"


def client_code(target: "Target") -> None:
"""
The client code supports all classes that follow the Target interface.
"""

print(target.request(), end="")


if __name__ == "__main__":
print("Client: I can work just fine with the Target objects:")
target = Target()
client_code(target)
print("\n")

adaptee = Adaptee()
print("Client: The Adaptee class has a weird interface. "
"See, I don't understand it:")
print(f"Adaptee: {adaptee.specific_request()}", end="\n\n")

print("Client: But I can work with it via the Adapter:")
adapter = Adapter()
client_code(adapter)
Client: I can work just fine with the Target objects:
Target: The default target's behavior.

Client: The Adaptee class has a weird interface. See, I don't understand it:
Adaptee: .eetpadA eht fo roivaheb laicepS

Client: But I can work with it via the Adapter:
Adapter: (TRANSLATED) Special behavior of the Adaptee.