Source code for uw.local.debug

"""Debug utilities.

Functions which may be useful for debugging.
"""

from functools import wraps
import timeit

def stopwatch (msg):
    """Create a decorator which may be used to time execution of a function.

    :param str msg: A message to print out when the wrapped function is timed.
    :return: A decorator which times the function to which it is applied and
        prints the time along with the specified message.
    """
    def decorator (f):
        @wraps (f)
        def wrapper (*args, **keys):
            start_time = timeit.default_timer ()
            result = f (*args, **keys)
            print ('%s: %s' % (msg, timeit.default_timer () - start_time))
            return result
        return wrapper
    return decorator

def sw (msg, f):
    """Call a function and time its execution.

    :param str msg: A message to print out when the wrapped function is timed.
    :param f: The function to time.  This must expect no parameters.  Providing
        a no-parameter lambda expression is likely to be useful.
    :return: The result of calling the wrapped function.
    """
    return stopwatch (msg) (f) ()