In one of our previous articles, we already looked at such a powerful tool as functions. And we learned how to define our subroutine in the code, add arguments, a block of instructions, and a return value to it. And also how to call it to solve problems further in the program text. Today, we will look at such an interesting tool as recursive functions in Python - this is important to know in order to pass DevOps courses / DevNet reviews Tashkent.
What is recursion, DevOps courses / DevNet reviews Tashkent
First of all, let's understand what recursion is. Of course, in relation to the topic of today's article - functional programming in Python. In this context, recursion is the addition of a function instruction that calls the same function again, but with new data. Typically, this is the data that was obtained as a result of the previous iteration of the function call. Of course, our DevOps / DevNet courses best Tashkent for IT specialists in Uzbekistan.
That is, if we analyze the principle of recursion, it looks like this: a program calls a subroutine, passing it data for processing as an argument. The first-generation subroutine processes them. And then it calls the second generation of the same subroutine, passing it the processed data as an argument for repeated processing. And so on, ideally, ad infinitum.
However, recursion has both advantages and disadvantages. The advantages of recursive functions include:
- ease of mastering the recursive programming method;
- the ability to solve complex problems with small blocks of code;
- high performance in tasks that can be broken down into a finite number of typical subtasks.
While among the disadvantages of this method the following are of the greatest importance:
- counterintuitiveness of the results of the work and increasing complexity of the algorithm analysis;
- an avalanche-like increase in the consumption of computer resources can fill up all available memory and load the CPU in a matter of seconds);
- high demands on the understanding of the process on the part of the programmer.
To sum it up, recursion is easy to learn, but can be difficult to use. And in inexperienced hands, this tool can bring no less headaches than benefits. And also become an ideal source of memory leaks in your project. Therefore, it is very important to learn how to use it correctly, and also to use it exactly where recursion gives the greatest benefit.
Examples of using recursion to solve problems in Python
Of course, recursive programming is a must-learn for anyone planning to take DevOps / DevNet courses reviews Tashkent. And become an IT specialist in Uzbekistan in 2024. Most likely, the simplest example of using recursion is getting the sum of numbers from 1 to n. Of course, you can use a loop to solve this problem. But the recursive solution will be a little shorter and will show the principle of the tool.
First of all, let's declare a function def rec_sum(n) and put a colon. On the next line, indented by 4 spaces, add a conditional operator and a check for equality to one — if n==1: and with an additional indent of 4 spaces - return 1. On the next line, on the same level as the conditional operator if — add a line containing a recursive algorithm: return n + rec_sum(n - 1).
As a result, the function will call more and more new versions of itself, each time decreasing the argument by one. Until it reaches zero, at which point the algorithm will stop. To learn more, we recommend going through DevOps / DevNet engineer courses Tashkent on the platform SEDICOMM.
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