# Yielding In Python w3schools

In this article, we will cover how to yield in Python. Yielding is a mechanism that allows an object to suspend its execution and allow another object to take control. This technique can be used in many situations, but we will focus on using it with the w3schools web API.

## What is yield?

Yield is a keyword in Python that allows you to pause the execution of a program and return a value. When yield is used, the program will stop executing until the next time yield is called. The next time yield is called, the value returned will be the result of the last statement executed.

For example, if you have a program that calculates the square of a number, you can use yield to pause the program and return the result of the square function. The code below shows how this can be done:

def square(n):
if n<0:
print(“Incorrect input”)
elif n==1:
return 0
. . .

square = yield square

## How to calculate yield

In Python, yield can be used to indicate that a function or loop should stop executing and return control to the caller. Yielding is similar to returning a value from a function, but it occurs within the function instead of at the end.

To understand how yield works, let’s look at an example. Say you have a function that takes two integers as input and prints out their sum. Here’s the code:

def sum(x, y): print(“Summing x and y”) return x + y

If you run this code, you’ll see that the output keeps coming even after you run the sum() function. This is because the return statement in sum() just returns the value of x + y, which continues to run even after the function is finished executing. This can be confusing, so let’s take a look at an example that will make things clearer.

In this example, we have a simple loop that sums up 10 numbers. The code looks like this:

def sum(n): for i in range(1, n+1): print(“Summing {}”.format(i)) yield i

## Returning values from a function

When you call a function in Python, the return value is what the function returns. This return value is usually a tuple (two items), but it can also be a single item.

The first item in the tuple is the result of the function call, and the second item is the return value of the function. The return value of a function can be anything that Python can interpret as a value. For example, a return value of a function might be an integer, a string, or even another function.

If you want to know what kind of value a particular return value represents, you can use the repr() function. repr() returns a string that shows how to interpret the return value. For example, if you call the min()function and pass it an integer as a parameter, repr() will return “int(min(x, y))”. This means that min() will take the lowest integer number from x and y and return it as a Python object.

## Introduction to recursion

Recursion is a powerful programming concept that allows you to solve problems by building upon previous solutions. In this article, we will learn how to use recursion in Python to solve a problem.

First, let’s take a look at the problem we will be solving: We want to find the sum of all odd numbers below 10. We can do this by first calculating the sum of each odd number from 2 up to 9, and then adding it all together. Here is the code for this:

sum = 0 for num in range(2, 9): sum = sum + num
Notice that we have used the keyword for in order to iterate over the numbers in range(2, 9). This syntax is called recursion because it works like the recursive calls you might hear on nature documentaries. In each iteration of the for loop, we are calculating the sum of num and then storing it in sum. We continue doing this until our loop terminates or until we reach 9. At that point, we simply return the value stored in sum—in this case, 5.

Now let’s see how we could have solved this same problem using recursion. The code below recursively calculates the sum

## The return value of a function

When you call a function in Python, the return value is what the function returns. This return value is always a single value, which is the result of the function execution.

There are two ways to return a value from a Python function: by assigning it to a variable or returning it as a string. Let’s look at an example to see how these work.

Suppose you have a function that takes two arguments and prints “Hello, world!” onscreen. To call this function, you could type the following code:

print(“Hello, world!”)

The first line calls the function and passes in the argument “Hello, world!” The second line prints “Hello, world!” onscreen. The return value of this function is “Hello, world!” because that’s what is printed onscreen when the function is executed.

## The return type of a function

When you call a function, the Python interpreter will return a value of the appropriate type. For instance, if you call a function that takes an integer as its argument, the interpreter will return an integer value.

If you want to return a different type of value than what was originally returned by the function, you can use the return statement. The return statement tells the interpreter to return a value of a specific type. For instance, if you want to return a string instead of an integer, you can use the return statement like this:

return “This is a string”

## Enhancing functions with inline functions

One of the most common enhancements you might want to make to a function in Python is to add inline functions. Inline functions are functions that are inserted directly into the code where they are used, rather than having them referenced from elsewhere in the code.

There are several reasons you might want to add an inline function. One reason is that you might want to make the function shorter. This can improve readability and maintainability of the code. Another reason is that you might want to improve performance. If the function can be executed in one step, it will run faster than if it needs to be called from multiple places in the code.

There are a few things to keep in mind when adding an inline function:

1. The function must be defined before it is used. This means that you cannot put the function definition inside a loop or other construct where it will be executed multiple times.

2. The function must have a __name__ attribute, which specifies its name within the interpreter. This allows you to reference the function by name rather than by its location in the codebase.

3. You must call the inline function with parentheses, just like any other function. This ensures that it will

## Summarizing a function

One of the most common tasks in programming is to take a set of input values and produce a corresponding set of output values. This is often done with functions, which are pieces of code that take one or more inputs and produce one or more outputs.

In this tutorial, we will learn how to summarize a function in Python. We will first create a function that takes two input values and produces an output value. Next, we will use the summarize() function to summarize our function. Finally, we will compare and contrast summarize() with the print() function.

Let’s get started! First, create a new file called summary.py and enter the following code:
def sum(x, y): return x + y

Next, let’s create a test datafile called data1.txt and enter the following lines of text:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71