Python function profiling time

time_profiler.py

#!/usr/bin/env python3

import time


class TimeProfiler:
    functions = list()
    start_time = instance = None

    def __init__(self):
        TimeProfiler.start_time = TimeProfiler.start_time or time.time()

    def __del__(self):
        total_time = time.time() - self.start_time
        one_percent = total_time / 100

        print("\nExecution time (total {:.2f} seconds):".format(total_time))

        for (fname, ftime) in self.functions:
            print("  - {}: {:.2f} seconds ({:4.1f}%) ".format(
                fname, ftime, ftime / one_percent
            ))

    def start(self, name):
        self.functions.append([name, time.time()])
        return len(self.functions) - 1

    def stop(self, index):
        self.functions[index][1] = time.time() - self.functions[index][1]

    @staticmethod
    def this(f):
        TimeProfiler.instance = TimeProfiler.instance or TimeProfiler()

        def wrapper(*args, **kwargs):
            try:
                index = TimeProfiler.instance.start(f.__name__)
                return f(*args, **kwargs)
            finally:
                TimeProfiler.instance.stop(index)

        return wrapper


@TimeProfiler.this
def a():
    print("a")
    time.sleep(0.1)


@TimeProfiler.this
def b():
    print("b")
    time.sleep(0.2)


@TimeProfiler.this
def c():
    print("c")
    # b()
    time.sleep(0.3)


@TimeProfiler.this
def d():
    print("d")
    a()
    b()
    c()
    time.sleep(0.4)


d()