examples of function decorators in python

1from functools import wraps
2
3def logit(func):
4    @wraps(func)
5    def with_logging(*args, **kwargs):
6        print(func.__name__ + " was called")
7        return func(*args, **kwargs)
8    return with_logging
9
10@logit
11def addition_func(x):
12   """Do some math."""
13   return x + x
14
15
16result = addition_func(4)
17# Output: addition_func was called
18

1from functools import wraps
2
3def logit(logfile='out.log'):
4    def logging_decorator(func):
5        @wraps(func)
6        def wrapped_function(*args, **kwargs):
7            log_string = func.__name__ + " was called"
8            print(log_string)
9            # Open the logfile and append
10            with open(logfile, 'a') as opened_file:
11                # Now we log to the specified logfile
12                opened_file.write(log_string + '\n')
13            return func(*args, **kwargs)
14        return wrapped_function
15    return logging_decorator
16
17@logit()
18def myfunc1():
19    pass
20
21myfunc1()
22# Output: myfunc1 was called
23# A file called out.log now exists, with the above string
24
25@logit(logfile='func2.log')
26def myfunc2():
27    pass
28
29myfunc2()
30# Output: myfunc2 was called
31# A file called func2.log now exists, with the above string
32