Timer¶

The code in this notebook helps with measuring time.

Prerequisites

This notebook needs some understanding on advanced concepts in Python, notably
- classes
- the Python with statement
- measuring time

Measuring Time¶

The class Timer allows to measure the elapsed time during some code execution. A typical usage looks as follows:

from Timer import Timer

with Timer() as t:
    function_that_is_supposed_to_be_timed()

print(t.elapsed_time())

In [1]:

import fuzzingbook_utils

In [2]:

import time

In [3]:

def clock():
    try:
        return time.perf_counter()  # Python 3
    except:
        return time.clock()         # Python 2

In [4]:

class Timer(object):
    # Begin of `with` block
    def __enter__(self):
        self.start_time = clock()
        self.end_time = None
        return self

    # End of `with` block
    def __exit__(self, exc_type, exc_value, tb):
        self.end_time = clock()

    def elapsed_time(self):
        """Return elapsed time in seconds"""
        if self.end_time is None:
            # still running
            return clock() - self.start_time
        else:
            return self.end_time - self.start_time

Here's an example:

In [5]:

def some_long_running_function():
    i = 1000000
    while i > 0:
        i -= 1

In [6]:

print("Stopping total time:")
with Timer() as t:
    some_long_running_function()
print(t.elapsed_time())

Stopping total time:
0.06727509300071688

In [7]:

print("Stopping time in between:")
with Timer() as t:
    for i in range(10):
        print(t.elapsed_time())

Stopping time in between:
4.9720001698005944e-06
5.465600042953156e-05
8.613899990450591e-05
0.00011476500003482215
0.00014296199879026972
0.00017072300033760257
0.00042000499888672493
0.00047452599937969353
0.0005045199995947769
0.0005325679994712118

That's it, folks – enjoy!