how to pass parameters of a function when using ti

Question

This is the outline of a simple program

# some pre-defined constants
A = 1
B = 2

# function that does something critical
def foo(num1, num2):
    # do something

# main program.... do something to A and B
for i in range(20):
    # do something to A and B
    # and update A and B during each iteration

import timeit
t = timeit.Timer(stmt="foo(num1,num2)")  
print t.timeit(5)

I just keep getting "global name foo is not defined"..... Can anyone help me on this? Thanks!

Answer 1

The functions can use arguments in timeit if these are created using closures, we can add this behaviours by wrapping them in another function.

def foo(num1, num2):
    def _foo():
        # do something to num1 and num2
        pass
    return _foo

A = 1
B = 2

import timeit
t = timeit.Timer(foo(A,B))  
print t.timeit(5)

or shorter, we can use functools.partial instead of explicit closures declaration

def foo(num1, num2):
    # do something to num1 and num2
    pass

A = 1
B = 2

import timeit, functools
t = timeit.Timer(functools.partial(foo, A, B)) 
print t.timeit(5)

Answer 2

I usually create an extra function:

def f(x,y):
    return x*y

v1 = 10
v2 = 20

def f_test():
    f(v1,v2)

print(timeit.timeit("f_test()", setup="from __main__ import f_test"))

Answer 3

I prefer creating a static class with all the Data ready to be picked up prior of running the timer.

Another note, it is better to do test runs in function rather then in the global space, as the global space isn't taking advantage of FAST_LOAD Why does Python code run faster in a function?

class Data(object):
    """Data Creation"""
    x = [i for i in range(0, 10000)]
    y = tuple([i for i in range(0, 10000)])
    def __init__(self):
        pass

import timeit

def testIterator(x):
    for i in range(10000):
        z = i


print timeit.timeit("testIterator(Data.x)", setup="from __main__ import testIterator, Data", number=50)
print timeit.timeit("testIterator(Data.y)", setup="from __main__ import testIterator, Data", number=50)

Answer 4

Another option is to bind the function to its arguments via functools (similar to std::bind). Then you don't need to pass arguments to timeit, the callable returned by functool.partial takes care of that:

    def findMax(n):#n is an array
        m = 0
        c = 0
        for i in range(len(n)):
            c += 1
            if m < n[i]:
                m = n[i]
        return m, c


import timeit
import functools
a = [6, 2, 9, 3, 7, 4, 5]
t = timeit.Timer(functools.partial(findMax,a))
t.timeit(100)

Answer 5

Supposing that your module filename is test.py

# some pre-defined constants
A = 1
B = 2

# function that does something critical
def foo(n, m):
    pass

# main program.... do something to A and B
for i in range(20):
    pass

import timeit
t = timeit.Timer(stmt="test.foo(test.A, test.B)", setup="import test")  
print t.timeit(5)