ex 7.2

logcall.py

@@ -1,6 +1,27 @@
-def logged(func):
+from functools import wraps
-    print('Adding logging to', func.__name__)
+
-    def wrapper(*args, **kwargs):
+
-        print('Calling', func.__name__)
+def logformat(message="Calling {name}"):
-        return func(*args, **kwargs)
+    def logged(func):
-    return wrapper
+        print(f'Adding logging to {func.__name__}')
+
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            fmtargs=dict(
+                name=func.__name__,
+                func=func,
+            )
+            print(message.format(**fmtargs))
+            return func(*args, **kwargs)
+        return wrapper
+    return logged
+
+
+logged = logformat()
+
+
+if __name__ == '__main__':
+    @logged
+    def add(x: int, y: int):
+        """Adds two numbers."""
+        return x + y

sample.py

@@ -1,4 +1,4 @@
-from logcall import logged
+from logcall import logformat, logged
 
 
 @logged
@@ -9,3 +9,29 @@ def add(x, y):
 @logged
 def sub(x, y):
     return x - y
+
+
+@logformat('{func.__code__.co_filename}:{func.__name__}')
+def mult(x, y):
+    return x * y
+
+
+class Spam:
+    @logged
+    def instance_method(self):
+        pass
+
+    @classmethod
+    @logged
+    def class_method(cls):
+        pass
+
+    @staticmethod
+    @logged
+    def static_method():
+        pass
+
+    @property
+    @logged
+    def property_method(self):
+        pass

validate.py

@@ -1,4 +1,5 @@
 import inspect
+from functools import wraps
 
 
 class Validator:
@@ -71,6 +72,7 @@ def validated(func):
     annotations = dict(func.__annotations__)
     retcheck = annotations.pop('return', None)
 
+    @wraps(func)
     def wrapper(*args, **kwargs):
         bound = sig.bind(*args, **kwargs)
         errors = []
@@ -91,6 +93,34 @@ def validated(func):
     return wrapper
 
 
+def enforce(**outerkwargs):
+    def enforced(func):
+        sig = inspect.signature(func)
+        retcheck = outerkwargs.pop('return_', None)
+        annotations = outerkwargs
+
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            bound = sig.bind(*args, **kwargs)
+            errors = []
+            for name, validator in annotations.items():
+                try:
+                    validator.check(bound.arguments[name])
+                except Exception as e:
+                    errors.append(f'   {name}: {e}')
+            if errors:
+                raise TypeError('Bad Arguments\n' + '\n'.join(errors))
+            result = func(*args, **kwargs)
+            if retcheck:
+                try:
+                    retcheck.check(result)
+                except Exception as e:
+                    raise TypeError(f'Bad return: {e}') from None
+            return result
+        return wrapper
+    return enforced
+
+
 class ValidatedFunction:
     def __init__(self, func):
         self.func = func
@@ -115,3 +145,7 @@ if __name__ == '__main__':
     @validated
     def power(x: Integer, y: Integer):
         return x ** y
+
+    @enforce(x=Integer, y=Integer, return_=Integer)
+    def mult(x, y):
+        return x * y