Python Timeit Decorator Function

This is a Python decorator which helps implementing an aspect oriented implementation of a retrying of certain steps which might fail sometimes. We can easily add the same functionality to some functions through the decorator. The name of the fixture function can later be referenced to cause its invocation ahead of running tests: test modules or classes can use the pytest. One of the applications of python function objects is Python Decorators. Statistical: Data is collected periodically and therefore what the profiler sees is a sample. This leads to many powerful ways to use functions. The main purpose of any decorator is to change your class methods or attributes in such a way so that the user of your class no need to make any change in their code. Here the -n 3 denotes the number of loops to execute. In the last example, we saw that a decorator can be used by passing it a function as an argument, thus 'wrapping' that function with the decorator function. As we discussed that we can decorate a function using decorators. Should a Python property decorator be used without a setter or deleter? 3. The simpler way to time a function is to define a decorator that measures the elapsed time in running the function, and prints the result:. Python decorators come in 2 related flavors. Therefore, in this post I’ll comment on 7 different Python tools that give you some insight about the execution time of your functions and the Memory and CPU usage. So, in the most basic sense, a decorator is a callable that returns a callable. Where the timeit. @property Decorator in Python. X, because function decorators are supported in both, and we use 3. Memoization is a way of caching the results of a function call. index # DatetimeIndex(['1970-01-01', '1970-01-02', '1970-01-03', '1970-01-04', '1970-01-05', '1970-01-06'], # dtype='datetime64[ns]', freq='D'). I found a rather complex example on Github that I used for some ideas on how to approach this task and came up with the following: In this code, we have two functions. In *both* cases the function (fib) only gets called once. In the last example, we saw that a decorator can be used by passing it a function as an argument, thus 'wrapping' that function with the decorator function. The resulting Cython source code will be compiled into optimized C or C++ code, and thereby yielding substantial speed-up of slow Python code. If you want to learn more about decorator functions I would suggest to read the python. The decorator pattern is a design pattern used in statically typed object-oriented programming languages to allow functionality to be added to objects at run time; Python decorators add functionality to functions and methods at definition time, and thus are a higher-level construct than decorator-pattern classes. python timeit script In a standard Python interpreter, you can access functions and other names you defined earlier during the interactive session by importing. Description. Timer (stmt='pass', setup='pass', timer=) ¶ Class for timing execution speed of small code snippets. There are no hard pre-requisites. Implementing timeout function with Process: As I said earlier threads can’t be killed because they have shared memory and some resources like files, database connections might be left unreleased if we kill the threads forcefully. Welcome to part 18 of the intermediate Python programming tutorial series. Now, using the these ways of writing, Python code can be used to create decorators. Anyways I just learned about this really cool feature yesterday and wanted to share. wraps return an 'async' function decorator if you pass an async function to decorate? It's indifferent? or it's necessary to create a new "functools. In WinPython-64bit-2. In many cases, a function decorator can be described more specifically: A function that takes one argument (the function being decorated) Returns the same function or a function with a similar signature; As Jack states in his talk, a decorator is merely syntactic sugar. decorated_function() only prints With argument 'Python', but the decorator adds an extra behavior that also prints Calling function 'decorated_function'. timeit('list(itertools. 2f sec' % \ ( method. That's why we have three levels of functions; the inner one is the actual replacement function. Line 11: We simply print out the execution time. time and time. Dobb's Journal, which I recommend if you want to understand them thoroughly. Decorators • If we execute this function, we get to see how often fibonacci is called on arguments already executed >>> fibonacci(10) Function fibonacci with arguments 1 ran in 5. Apart from OpenCV, Python also provides a module time which is helpful in measuring the time of execution. This leads to many powerful ways to use functions. 1 Prerequisite. In Python, functions are treated as first class objects, allowing you to perform the following operations on functions. Python binds the result of the decorator evaluation to the original function name, someFunction(). We'll focus on the timeit() function in this module. time and time. Python decorators are a powerful concept that allow you to "wrap" a function with another function. Higher-order functions are also baked into everyday Python via decorators. The second function is our decorator function. 4 provided support to wrap a function in a decorator by pre-pending the function definition with a decorator name and the @ symbol. A function profiler will observe how long each function runs. If a decorator expects a function and 5 returns a function (no descriptors), and if it doesn't 6 modify function attributes or docstring, then it is 7 eligible to use this. time, me ha resultado útil al momento de desarrollar. The basic requirement comes when you want to see how much time your methods are taking. You will note that we pass a call to the. In this sense, a decorator is a callable that returns a callable, e. 4, and on class statements since Python 2. Here we wrap the passed in function in a try/except and log any exceptions that occur using our logger. Note the same technique can be used to do things before and after functions. More specifically, a decorator is a function that transforms another function. If a function contains at least one yield statement (it may contain other yield or return statements), it becomes a generator function. A simple example is:. Python decorator are the function that receive a function as an argument and return another function as return value. A magic function begins with either a % or %% sign. Because wrapper() is a regular Python function, the way a decorator modifies a function can change dynamically. Implementation of Timeit function, Get performance numbers for a function This is regarding the timeit implementation in python. The first will simply increment a counter. …But, in fact, in this chapter, we've already seen…all that we need to understand them. Pythonish python Langtangen #2: The docstring. The First Decorator Is Called Strong And Has An Inner Function Called Wrapper. This is why decorators are also called 'wrappers'. __name__ , args , kw , te - ts ) return result return timed. Decorators¶ Now we have a decent understanding of first class objects , *args and **kwargs , we can show how decorators work. Every other function in the total recorded, were called just the once. The if __name__ == '__main__' section calls and runs the script. More specifically, a decorator is a function that transforms another function. the function becomes a function factory. For example, the svd function returns a single output, s, or three outputs, [U,S,V]. It uses a platform-specific time function to provide the most accurate time calculation possible. This function can be used both as a line and cell magic as explained here −. The name of the fixture function can later be referenced to cause its invocation ahead of running tests: test modules or classes can use the pytest. For any of your own functions the rule is: You can only call functions, that are also compiled by Numba (by adding e. register() and signal. If you want to learn more about decorator functions I would suggest to read the python. Accelerate Python Functions. If a function contains at least one yield statement (it may contain other yield or return statements), it becomes a generator function. Time a Python Function Without Arguments. Multiple Decorators for python functions A decorator is typically a function that takes a function as an argument and then will do something with that function before calling that function. So that can wrap any function with any number of arguments just by putting @cache before it. This banner text can have markup. The output of the timeit decorator function looks like this: 'longRunningOperation' (('test', 'optional test'), {}) 3. Anonymous functions are also called lambda functions by Python programmers. timeit('list(itertools. Decorators are very powerful and useful tool in Python since it allows. When you start refining your Python programs, one of the most useful things to do is to time how fast individual functions run. However, Python also has a syntax pattern that makes this more intuitive and easier to read once you are comfortable with decorators. This decorator can be used, with or without parameters, to define a fixture function. In Python 2. Using pyopencl to implement the mandel function with an NVIDIA K80 backend, the following timing was measured (for code see the notebook on GitHub): In[4]: %timeit mandel_set7(-2, 0. Now we seen decorators, those are for decorating functions. A magic function begins with either a % or %% sign. DECORATORS • Decorator expressions are evaluated when the function is defined, in the scope that contains the function definition. Python @property is one of the built-in decorators. The assumption for a decorator is that we will pass a function as argument and the signature of the inner function in the decorator must match the function to decorate. Memoization in python using a decorator: getting a prime number. At the exit of the decorated function (regular exit or exceptions), the local dictionary is copied to a read-only property, locals. Even though it is the same underlying concept, we have two different kinds of decorators in Python: Function decorators Class decorators A decorator in Python is any callable Python object that is used to modify a function or a class. Clone via HTTPS Clone with Git or checkout with SVN using the repository’s web address. Suppose you have 2 functions f1, f2, with different implementations. One small consequence of the different context is that we often, must explicitly name the self variable in decorators intended for methods. 萬惡的 Python Decorator 究竟是什麼? 初學 Python 時,我覺得 decorator 很難理解,Google 到幾篇中英文網誌,每篇講的都不太一樣,只好把網誌多看幾遍,拼拼湊湊找線索,終於理解 decorator 是什麼,趕快來寫一下我所理解的 decorator 。. The timeit module uses platform-specific time functions so that you will get the most accurate timings possible. 7: Write The Following Decorators And Apply Them To A Single Function (applying Multiple Decorators To A Single Function): 1. Decorator in Python is a syntax sugar for high-level function. and there are some tools made for this purpose. This involves a function that operates on a function, known as a higher-order function. Pics of : Timeit Decorator Python 3. 3 The timeit module provides a simple interface for determining the execution time of small bits of Python code. Decorators are a way to uniformly modify functions in a particular way. Cython at a glance¶. timeit模块提供了测量Python小段代码执行时间的方法。它即可以在命令行界面直接使用,也可以通过导入模块进行调用。该模块灵活地避开了测量执行时间所容易出现的错误。 以下是命令行界面使用的例子:. Python 3 range is actually a generator in the mode of Python 2 xrange, and there is no Python 3 xrange. Anyone who knows how to write a Python function can learn to use a decorator:. Note: 使用 closure 去處理 function. mydata = generate_data(xyz) f1(mydata) f2(mydata). The decorator pattern is a design pattern used in statically typed object-oriented programming languages to allow functionality to be added to objects at run time; Python decorators add functionality to functions and methods at definition time, and thus are a higher-level construct than decorator-pattern classes. The final two lessons of the course are all about Python decorators, functions that you can use to wrap other functions and modify their behavior. Frame with Python code contained within each API call. Within this function is a nested function called inner which prints “Hello” to the console. In this tutorial, learn how to implement decorators in Python. Although it’s not possible to decorate a lambda with the @decorator syntax, a decorator is just a function, so it can call the lambda function:. With decorators, you can modify the functionality of a method. % timeit-n 3 func (10, 0. The basic requirement comes when you want to see how much time your methods are taking. setup which is the code that you run before running the stmt; it defaults to 'pass'. The main purpose of any decorator is to change your class methods or attributes in such a way so that the user of your class no need to make any change in their code. The decorator function is called with a single parameter which is the constructor function being decorated. 015 seconds 4. Python decorators, I think, are best equated to macros I think it's safe to say that the goal of macros in a language is to provide a way to modify elements of the language. There are some built-in decorators. In the above example timeit() decorator will calculate the time taken by the function to execute. Frame decorators have a mandatory interface, defined below. You use the docstring for structured documentation for yourself and oth-ers, explaining the class, method, function, module. Numba-compiled numerical algorithms in Python can approach the speeds of C or FORTRAN. Time execution of a Python statement or expression using the timeit module. Now let’s look a bit closer at generators. In the code samples above we decorated our function by replacing the variable containing the function with a wrapped version. The assumption for a decorator is that we will pass a function as argument and the signature of the inner function in the decorator must match the function to decorate. Functions objects¶ Since Python pushes the object-oriented paradigm to its maximum, it makes a point of always following the tenet everything is an object. The calling function is a factory. For example, in functools you have the wraps decorator. A free online tool to decompile Python bytecode back into equivalent Python source code. Python中的对象都可以通过调用id和type获得自己的唯一标识和类型,例如方法的类型是function,类的类型是type,在上面代码也可看出这些对象都是可以进行传递的。 我们现在已经知道,方法也是对象,也有自己的方法和属性,而且是可传递执行的。 闭包. Notice the double percentage sign: %% timeit-n 3 func (10, 0. The resulting Cython source code will be compiled into optimized C or C++ code, and thereby yielding substantial speed-up of slow Python code. We will be using an in-built python library timeit. The wrapt module ensures that your decorators will work in all situations. For some problems, there is no convenient way to solve them with NumPy alone. add new behaviour (classical decorator pattern from GoF book) replace decorated object with something else. In the last example, we saw that a decorator can be used by passing it a function as an argument, thus ‘wrapping’ that function with the decorator function. In my mind, although terminology. However, when the deco-rated function is called, the situation is exactly reversed; the inner function of the top decorator runs first, followed by the second from the top, and so on. Docstrings and simple testing:doctest Docstring and automatic generation of documentation: Sphinx: Python documentation generation. If a function is memoized, evaluating it is simply a matter of looking up the result you got the first time the function was called with those parameters. Functions objects¶ Since Python pushes the object-oriented paradigm to its maximum, it makes a point of always following the tenet everything is an object. Context Managers. You will note that I am also logging the. The list can go on and on. With decorators, you can modify the functionality of a method. We shall deal with functions for this tutorial. pyc extension (valid for python 2. Now let's say you have both func and gunc in a cell, and you want to measure the time taken, then you can use %%timeit in the block. Jupyter Notebook relies on the literate programming approach originally advanced by Donald Knuth. 25, 1000, 1000, 80) 26. org wiki article on decorators. ) The syntax for "decorator" is @name1 immediately before the line of def name2. Python 3 range is actually a generator in the mode of Python 2 xrange, and there is no Python 3 xrange. Decorators on function statements have been available since Python 2. Ask Question Asked 3 years, 11 months ago. In this course you will learn how to write code, the basics and see examples. This document covers the creation of decorators and all the information needed to cover what you can do within the wrapper function linked to your decorator. Check out profilehooks on PyPI for something like this at function level, implemented using decorators. They are different things. Search the history of over 384 billion web pages on the Internet. how to use xrange() in Python 2. Decorator Function 沒有參數的 Function 版本. Please do not confuse the Decorator Pattern (or an implementation of this design pattern in Python - as the above example) with Python Decorators, a Python language feature. They are different things. is equivalent to creating acomposite function func= decorator(arg)(func) # decorator(arg) must be a decorator St ephane Vialette (LIGM, Universit e Paris-Est Marne-la-Vall ee)Python Decorators October 12, 2009 20 / 25. Sep 21, 2017 • Zhuyi Xue. One way is to use the python inbuilt time module and save the time before and after the execution of the program? Python timeit. So, in the most basic sense, a decorator is a callable that returns a callable. So that can wrap any function with any number of arguments just by putting @cache before it. An example of this is Flask. The more usual Python way of doing this is to use a Clss instance. If I put some statement like @app. The markup used for the Python documentation is reStructuredText, developed by the docutils project, amended by custom directives and using a toolset named Sphinx to post-process the HTML output. A coroutine function (async def) are used to create a coroutine for an event loop. Python Decorator 可以以 function 與 class 實作出來,且有無參數的寫法也會因此不一樣,以下記錄了從 Stack Overflow 學習來的 decorator 寫法 {function, class} X {with, without} arguments = 4 種. You will note that we pass a call to the. GitHub Gist: instantly share code, notes, and snippets. The list can go on and on. I am so over that and gave up caring when my will to work on WSGI stuff was leached away by how long it took to get the WSGI specification updated. Profiling repetition of elements in an array >>> import timeit >>> timeit. ) - python_decorator_guide. A function can help programmers to wrap their logic into a task for avoiding duplicate code. As you can see, the my_decorator() function dynamically creates a new function to return using the input function, adding code to be executed before and after the original function runs. The main purpose of any decorator is to change your class methods or attributes in such a way so that the user of your class no need to make any change in their code. The assumption for a decorator is that we will pass a function as argument and the signature of the inner function in the decorator must match the function to decorate. I found a rather complex example on Github that I used for some ideas on how to approach this task and came up with the following: In this code, we have two functions. … Easy Timeit Function in Python Python provides a module timeit which allows quick timing of a piece of code. Python Interface ¶ The module defines three convenience functions and a public class: timeit. 8 as your interpreter in PyCharm (if you’re not sure how to switch the interpreter, jump into our documentation for help). Python decorators are a wrappers around the function/method/class that can do actions before/after some function/method/class is invoked. python timeit script In a standard Python interpreter, you can access functions and other names you defined earlier during the interactive session by importing. Now, the nested function will grab the time before calling the passed in function. The following two posts are very comprehensive and yet easy to follow and should suffice for most purposes Understanding Python Decorators in 12 Easy Steps! A guide to Python's function decorators | The Code Ship You might also want to check the. This abstraction is necessary to maintain integrity of the data contained in each gdb. The second function is our decorator function. Numba provides Python developers with an easy entry into GPU-accelerated computing and a path for using increasingly sophisticated CUDA code with a minimum of new syntax and jargon. The simpler way to time a function is to define a decorator that measures the elapsed time in running the function, and prints the result:. We'll make use of the timeit module to compare the actual performance of different object-oriented designs and Python constructs. Python Function And Python Closure; Python Decorators; All examples in this article use Python 3. You can start with simple function decorators to automatically compile your functions, or use the powerful CUDA libraries exposed by pyculib. Python - Cache function and decorator. They are different things. And the display_arguments defines a new function called display_and_call, which is a modified version of the wrapped function. Python Python: Using a custom decorator to inspect function arguments The ability to use introspection to dynamically determine the current code context and frame/stack can be a powerful tool for a developer. Timer (stmt='pass', setup='pass', timer=) ¶ Class for timing execution speed of small code snippets. The first one creates a logging object and. This is why decorators are also called ‘wrappers’. Roy Smith pisze: It seems desirable that we choose words which are as close as possible. what are functions in python decoration for function function in python example classes and functions in python how to make functions in python first class functions python python same function name different parameters call function from class python painters & decorators painter decorator python decorator with arguments python decorator. ) So once a function is decorated, it’s decorated for all the code. If the function specified by f has a variable number of outputs, numOutputs specifies which syntax timeit uses to call the function. O(1) - (Constant performance) Execution time stays constant regardless of how much data is supplied. When python sees \@display_arguments, it calls the display_arguments with the wrapped functions (my_add or my_deduct) as the argument. This is called metaprogramming. Frame from the decorated data produced by a frame decorator. They are excellent as an introduction to the topic, but they just scratch the surface of the power decorators can bring to your application. ) The syntax for "decorator" is @name1 immediately before the line of def name2. Using the Python @decorator syntax, it receives the decorated function as an argument, just like in my example: some_func_decorated = my_decorator(some_func). This has very. Python for Beginners [32 of 44] Demo: Parameterized Functions 04:40 Related episodes. Context Managers. In brief, decorators are callable objects that accept the function they decorate as their sole argument. Python timeit decorator. This nested function must refer to a variable nonlocal to it(a variable in the scope enclosing it). timeit模块--准确测量小段代码的执行时间. Note that as execution time may depend on its input and the function itself is destructive, I make sure to use the same input in all the timings, by copying the original shuffled array into the new one. 1 def simple_decorator (decorator): 2 '''This decorator can be used to turn simple functions 3 into well-behaved decorators, so long as the decorators 4 are fairly simple. That's what decorators do in Python -- they modify functions, and in the case of class decorators, entire classes. ) in Python. Anonymous functions are also called lambda functions by Python programmers. The standard way to memoize functions in python is just with a simple decorator, but a super simple caching mechanism can also create memory pressure and incur a trade-off that leads to a whole new set of problems. decorators import jit , autojit pairwise_numba = autojit ( pairwise_python ) % timeit pairwise_numba(X). (This gets better from Python >= 2. You can think of them as functions that take functions as input and produce a function as output (as explained on this page by Matthew Brett). Welcome to part 18 of the intermediate Python programming tutorial series. If the function specified by f has a variable number of outputs, numOutputs specifies which syntax timeit uses to call the function. So as not to disturb your neighbors, the following example will only run the decorated code during the day:. Consider this awesome decorator in django. Python decorators add functionality to functions and methods at definition time, they are not used to add functionality at run time. Python provides many ways to measure the time of execution for a piece of python code. So, in the most basic sense, a decorator is a callable that returns a callable. Mayank Tripathi Re: How can I make a chain of function decorators in Python?. Those with a % sign work within the environment, and those with a %% sign work at the cell level. They are extracted from open source Python projects. ' Decorators are most often used to extend a function, by adding something either before or after it. In this sense, a decorator is a callable that returns a callable, e. python -m timeit "'Hello, world!'. The Purpose Of This Decorator Is To Add The Html Tags Of And To The Argument Of The Decorator. They are part of the functional paradigm incorporated in Python. The return value of the decorator function must be a function used to wrap the function to be decorated. To find the execution time using decorators, we need to define a class named TimeIt over-writing the __call__ function to measure the time taken to execute the function. Available In: 2. Python timeit Functions. To make it simpler see below: function validator() { return function (target) { target. You can vote up the examples you like or vote down the ones you don't like. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. The return value of the decorator function must be a function used to wrap the function to be decorated. We will be using %timeit, an in-built magic function of iPython notebook environment. python timeit script In a standard Python interpreter, you can access functions and other names you defined earlier during the interactive session by importing. Functions can be defined inside another function and can also be passed as argument to another function. default_timer(). They are excellent as an introduction to the topic, but they just scratch the surface of the power decorators can bring to your application. In Python, a decorator is a design pattern that we can use to add new functionality to an already existing object without the need to modify its structure. I am so over that and gave up caring when my will to work on WSGI stuff was leached away by how long it took to get the WSGI specification updated. The implicit contract is that the decorator will return another function that will be called in place of the decorated function. The final two lessons of the course are all about Python decorators, functions that you can use to wrap other functions and modify their behavior. Instead, we have to pass a function to the common function. The code below does 2D discrete convolution of an image with a filter (and I’m sure you can do better!, let it serve for demonstration purposes). Whenever You import a module, CPython compiles it to byte code, and saves it using the same path and filename, except for a *. 萬惡的 Python Decorator 究竟是什麼? 初學 Python 時,我覺得 decorator 很難理解,Google 到幾篇中英文網誌,每篇講的都不太一樣,只好把網誌多看幾遍,拼拼湊湊找線索,終於理解 decorator 是什麼,趕快來寫一下我所理解的 decorator 。. Python的decorator,有带参数和无参数两种,带参数的decorator采用了三层嵌套,使用decorator用Python提供的@语法,这样可以避免手动编写f=decorate(f)这样的 博文 来自: qq_34091847的博客. Before moving on, let's have a look at a second example. Python comes with a module called timeit. Function(s) execution timer @decorator with args --> functions wrapper for a quick Python Built-in 'Timeit' modile reports without interrupting or breaking course of a code run. timeit module. Decoration is a very basic and practical feature of python. Python sports a powerful, mysterious feature called the decorator. How can I make a time delay in Python? How to make a chain of function decorators? How do I pass a variable by reference? How to get the number of elements in a list in Python? How to concatenate two lists in Python? How do I access environment variables from Python? Why does Python code run faster in a function?. Python List Comprehension Tutorial Learn how to effectively use list comprehension in Python to create lists, to replace (nested) for loops and the map(), filter() and reduce() functions, ! When doing data science, you might find yourself wanting to read lists of lists, filtering column names, removing vowels from a list or flattening a matrix. Explore Python’s major built-in object types such as numbers, lists, and dictionaries Create and process objects with Python statements, and learn Python’s general syntax model Use functions to avoid code redundancy and package code for reuse Organize statements, functions, and other tools into larger components with modules. 2f sec' % \ ( method. Decorators on function statements have been available since Python 2. A function can take a function as argument (the function to be decorated) and return the same function with or without extension. Python Essential Training and functions; and how to work with generators and decorators. let's look at a piece of code to record the runtime:. 0 on May 2017. So I thought I'd try my hand at writing an introduction to Python decorators. Time execution of a Python statement or expression uses the timeit module. Note the same technique can be used to do things before and after functions. The decorator works in an abstract style to extend or completely replace the behavior of an object. Once you've learned basic python,this is a great resource. functions, the decorators run inside out, i. Should a Python property decorator be used without a setter or deleter? 3. You can then run it with python -m memory_profiler myscript. Use a decorator to time your functions. Docstrings and simple testing:doctest Docstring and automatic generation of documentation: Sphinx: Python documentation generation. This pattern is very common in Python applications, as it allows two or more subsystems to communicate without knowing much about each other, what is formally known as a "decoupled" design. Here are three examples of Python decorators for people who know how to use them, but forget how to write them. Decorator Benchmarks¶. Decorators are  a powerful and useful feature in Python since it allows programmers to modify the behavior of function or class. Multiple decorators on a single function are applied bottom to top (decorator. the decorator closest to the func-tion runs first, followed by the second closest, etc. time ( ) result = method ( * args , ** kw ) te = time. Therefore, in this post I’ll comment on 7 different Python tools that give you some insight about the execution time of your functions and the Memory and CPU usage. Basically, a decorator takes in a function, adds some functionality and returns it. Time a Python Function Without Arguments. Cython expecting a numpy array - naive; Cython expecting a numpy array - optimised; C (called from Cython). You can find all the examples from this article here. Keep that in mind. Implementation of Timeit function, Get performance numbers for a function This is regarding the timeit implementation in python. Python: Using a custom decorator to inspect function arguments The ability to use introspection to dynamically determine the current code context and frame/stack can be a powerful tool for a developer. You can start with simple function decorators to automatically compile your functions, or use the powerful CUDA libraries exposed by pyculib. It actually works the same way as the xrange does. This is because when you use the @my_decorator syntax, you are applying a wrapper function with a single function as a parameter Remember, everything in Python is an object, and this includes functions! With that in mind, we can write a function that returns a wrapper function. A Python decorator for measuring the execution time of methods As Python developer you often have the need for profiling and benchmarking applications. Timer (stmt='pass', setup='pass', timer=) ¶ Class for timing execution speed of small code snippets. From there you will just need to switch to Python 3. Taking the running time of the measuring function as an example, we will talk about the operating principle of Python decorator.