marp, paginate, theme, footer, header, math
| marp | paginate | theme | footer | header | math |
|---|---|---|---|---|---|
| true | true | rose-pine | Tutorium 14 - 26.01.2024 - Nils Pukropp - https://s.narl.io/s/tutorium-14 | mathjax |
Tutorium 14 - 02.02.2024
Decorator, Testing
Decorator
- Design-Pattern, oft auch Wrapper genannt
- Verpackt ein Objekt um zusätzliche Funktionalität zu bieten
- Funktionen sind auch Objekte
- eine Klasse ist ein Objekt
- Oft einfach syntax sugar
Beispiel - execute_two_times
def execute_two_times(fn: Callable[..., Any]) -> Callable[..., Any]:
def wrapper(*args, **kwargs)
fn(*args, **kwargs)
fn(*args, **kwargs)
return wrapper
return wrapper
@execute_two_times()
def print_two_times(msg: str):
print(msg)
print_two_times("hello") # hello
# hello
Beispiel - execute_by
def execute_by(n: int):
def wrapper(fn):
def wrapped_fn(*args, **kwargs):
for _ in range(0, n):
fn(*args, **kwargs)
return wrapped_fn
return wrapped_fn
return wrapper
@execute_by(10)
def print_ten_times(msg: str):
print(msg)
print_ten_times("hello") # hello
# hello
# ... (10 mal)
Beispiel - CommandExecutor
class CommandExecutor[R]:
def __init__(self):
self.__commands: dict[str, Callable[..., R]] = {}
Beispiel - run
def run(self, name: str, *args, **kwargs) -> list[R]:
results : list[R] = []
for command_name, command in self.__commands.items():
if command_name == name:
results += [command(*args, **kwargs)]
return results
Beispiel - register
def register(self, cmd: Callable[..., R]) -> Callable[..., R]:
self.__commands[cmd.__name__] = cmd
return cmd
Beispiel - CommandExecutor
class CommandExecutor[R]:
def __init__(self):
self.__commands: dict[str, Callable[..., R]] = {}
def run(self, name: str, *args, **kwargs) -> list[R]:
results : list[R] = []
for command_name, command in self.__commands.items():
if command_name == name:
results += [command(*args, **kwargs)]
return results
def register(self, cmd: Callable[..., R]) -> Callable[..., R]:
self.__commands[cmd.__name__] = cmd
return cmd
Beispiel - How to use
app = CommandExecutor[str]()
@app.register
def hello_world() -> str:
return 'hello_world'
@app.register
def divide(a: int, b: int) -> str:
if b == 0:
return "tried to divide by zero"
return str(a / b)
print(app.run('hello_world'))
print(app.run('divide', 5, 0))
print(app.run('divide', 10, 2))
Decorator in der Klausur
- Waren noch nie Bestandteil der Klausur
- Mut zur Lücke
- Kann euch natürlich nichts versprechen