What is Reduce Function and its Implementation

In this blog, we would discuss What is Reduce Function and its Implementation. Python’s reduce() function is used to apply a function to a sequence of items, from left to right, so as to reduce the sequence to a single value. For example, if you were to use the reduce() function to add up all the numbers in a list, you could pass in the addition function and the list of numbers.

 

 

The reduce() function takes two arguments: a function and a sequence. The function is called with two arguments, the first of which is the “running total” and the second is the next item in the sequence. The function returns the updated running total

 

 

 

What is Reduce Function?

 

In Python, the reduce() function is used to apply a given function to a sequence of elements present in a list, tuple, or any other iterable object. It is often used to perform some kind of computation or other operation on a list of elements. The reduce() function takes two arguments: a function and a sequence. The function must take two arguments and return a single value.

 

 

The reduce() function applies the function to the first two elements of the sequence and then applies the function to the result and the third element and so on. If the given sequence contains only one element, then that element is returned by the reduce() function.

 

 

In other words, Reduce is a function that takes in an iterable and applies a function to it in an accumulative manner. Essentially, this means that the first element in the iterable is used as the first argument to the function, the second element is used as the second argument to the function, and so on. The return value of the function is then used as the first argument to the function for the next element in the iterable, and so on. The result of this is a single value that is the result of applying the function to the iterable.

 

 

 

Implementation of Reduce Function

 

Reduce is a function that applies a given function to a sequence of elements from left to right, so as to reduce the sequence to a single value. For example, suppose we have a sequence of numbers and we want to find their sum. We can do this by using the reduce function and passing in the additional function as the first argument:

 

from functools import reduce
sequence = [1, 2, 3, 4, 5] 
result = reduce(lambda x, y: x + y, sequence) 
print(result)

 

 

 

In the example above, the reduce function takes in the lambda function as the first argument. The lambda function takes two arguments, x, and y, and returns the sum of these two numbers. The reduce function then applies this function to the sequence of numbers from left to right. So, the first two numbers in the sequence are 1 and 2, and the result of the lambda function is 3.

 

 

The next two numbers in the sequence are 3 and 4, and the result of the lambda function is 7. The last two numbers in the sequence are 4 and 5, and the result of the lambda function is 9. The final result of the reduce function is 15. For example, we can use the reduce function with the max function to find the maximum value in a sequence:

 

sequence = [1, 2, 3, 4, 5] 
result = reduce(lambda x, y: max(x, y), sequence)
print(result)

 

 

 

In the example above, the lambda function takes two arguments, x, and y, and returns the maximum of these two numbers. The reduce function then applies this function to the sequence of numbers from left to right.

 

You can also use the reduce() function with a built-in function. For example, the following code multiplies all the numbers in a list:

 

from functools import reduce
lst = [1, 2, 3, 4, 5] 
m=reduce(lambda a, b: a*b, lst)
print(m)

 

 

The reduce() function is a powerful tool for processing sequences. It can be used to perform all sorts of data processing tas s, from simple addition to more complex tasks such as multiplication or division.

 

 

Also, read about the Filter Function.