The number of times a function gets called in Python
Let's say I want to integrate
x**2 from 0 to 1. I do it using the
from scipy import integrate def f(x): return x**2 I = integrate.quad(f, 0, 1) print(I)
Questions: Is there any way to know how many times the user-defined function
f gets called by the
quad? I want to do it as I am interested to know how many have been utilized by
quad to evaluate the integral.
Sure. Use a call-counting wrapper:
import functools def counted_calls(f): @functools.wraps(f) def count_wrapper(*args, **kwargs): count_wrapper.count += 1 return f(*args, **kwargs) count_wrapper.count = 0 return count_wrapper
And pass the wrapped version to
wrapped = counted_calls(f) integrate.quad(wrapped, 0, 1) print(wrapped.count)
Demo, with a call count of 21.
I've specifically avoided using a global counter or using
counted_calls as a decorator on the
f definition (though you can use it as a decorator if you want), to make it easier to take separate counts. With a global, or using it as a decorator, you'd have to remember to manually reset the counter every time.
Python Tutorial: Count Function calls with the help of a Metaclass, Use Cases for Metaclasses: Counting Function Calls. makes it possible to count the number of times each method of the subclass has been called. We can get the list of all the non private attributes of a class - in our example the random No less. Three shalt be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, neither count thou two, excepting that thou then proceed to three. Five is right out.
You could do something like this:
from scipy import integrate class FWrap(object): def __init__(self): self.count = 0 def f(self, x): self.count += 1 return x ** 2 fwrap = FWrap() f = lambda x: fwrap.f(x) I = integrate.quad(f, 0, 1) print(I) print(fwrap.count)
I prefer this to globals, though there's probably a simpler way. (EDIT: There is)
Count the number of times a function runs, Just call the function code 16 times for each tick of the counter. You could make it so that for every external call of function A , A is called another 999,999 times internally. Let’s begin this tutorial and explore the essential Python time functions, structures, and their usage. Get Started with Python Time Module. Every computer system comes with a clock pre-programmed to a specific date, time, and time zone. Python time module provides the ability to read, represent, and reset the time information in many ways.
Just add to a global whenever
f is called:
from scipy import integrate count = 0 def f(x): global count count += 1 return x ** 2 I = integrate.quad(f, 0, 1) print(I) print('called', count, 'times')
python, keep track of how many times a function has been accessed def myfunc(a an item each time the function is called""" # put your function code here, way - how are you keeping count from getting wiped off the runtime stack? The beginning of time is started measuring from 1 January, 12:00 am, 1970 and this very time is termed as “epoch” in Python. Operations on Time : 1. time() :- This function is used to count the number of seconds elapsed since the epoch.
In your small example, you can use variables or some other custom code to keep track, but if you'd rather not have to keep editing your code (maybe in a large program where you want to track many functions' calls), it'd be better to use trace and/or some call graphing library. More standard approach too, and gives you other things like timing data if you want it.
I've used this one with Gprof before and was happy with it, and it works for more than just Python: https://github.com/jrfonseca/gprof2dot
Python list function, count() is an inbuilt function in Python that returns count of how many times a given object occurs in list. Syntax : list_name.count(object). Parameters : Object is the Usually, we prefer importing and passing the Python function as a callable object into timeit.timeit since it's more maintainable. In addition, remember that the default number of executions is 1000000 which could increase the total execution time a lot for certain complex functions.
You can add a simple counter inside the function to tally how many times the specific code was ran.
6. Iteration, In Python, an assignment statement can make two variables equal, but they This means get the current value of x, add one, and then update x with the Here is a function called countdown that demonstrates the use of the while statement: When the loop exits, count contains the result – the total number of times the Python datetime functions are provided by the library named datetime and in order to use date time functions we need to import this library like below. from datetime import datetime Date and Time. While using pythons datetime functions, libraries and data structures we will involve with two basic data structures date and time.
3. Functions, Function calls contain the name of the function being executed followed by a list For example, a short way to print nine consecutive new lines is to call three_lines three times. Python has a built-in function for computing the absolute value:. def measureTime(a): start = time.clock() a() elapsed = time.clock() elapsed = elapsed - start print "Time spent in (function name) is: ", elapsed. python time callback. Share a link to this question. improve this question. asked Mar 29 '11 at 20:12. 49 silver badges. 83 bronze badges. Python profiling tools can show you function names and time
Functions · GitBook, We define a function called say_hello using the syntax as explained above. just input to the function so that we can pass in different values to it and get back the value of the name x with the first line in the function's body, Python uses We achieve this by specifying a default argument value of 1 to the parameter times . To get the calling function's name instead, consider f_back as in inspect.currentframe ().f_back.f_code.co_name. If also using mypy, it can complain that: error: Item "None" of "Optional [FrameType]" has no attribute "f_code" To suppress the above error, consider: import inspect import types from typing import cast this_function_name = cast
6.6. Functions can Call Other Functions, The second function called sum_of_squares makes use of square to compute the sum in practice this example illustrates many very important Python concepts, Unlike the case of the square, we cannot repeat the same thing 4 times, def drawRectangle(t, w, h): """Get turtle t to draw a rectangle of width w and height h. Python Functions. ❮ Previous Next ❯. A function is a block of code which only runs when it is called. You can pass data, known as parameters, into a function. A function can return data as a result.