Don't worry. Not everyone knows it...

Before jumping on to what is reduce, let’s have a quick look at the lines  below :  import operator sum = 0 for n in [1,2,3]: sum = sum + n print ( sum ) You got it right. Here we are taking a collection having three numbers and summing them up. As such, there is nothing wrong with this code but, of course there is a big room for optimization with respect to the number of lines of code we have written, just go get summation. Now the question is, how can we optimize? How can we reduce the number of lines and achieve the same result? Well, the answer is reduce function. What is reduce? Reduce is a function in Python provided by functools . This function takes a collection of values, performs some operation by calling a function and then returns a single value as an output. For example, you can give multiple values as input and perform mathematical calculations on them, you can perform operations on multiple strings, etc. Ways to use reduce There are two ways you can use redu...

In this article, I’m going to share a scenario wherein we need to get a key from a Python dictionary, which is holding maximum value. Usually we are required to get a key having maximum key from a dictionary, which, of course, most of us can do very easily. But when it comes to the other way round, it is not that straight forward. I also found that this is one of the hottest questions these days for interviewers :) To achieve the scenario of a dictionary key having maximum value, we can go with two different ways as mentioned below: Method 1: Using itemgetter()  import operator students = {'Shweta':25,'Andy':30,'Maddy':3} v = max(students.items(),key=operator.itemgetter(1))[0] print ( v ) Method 2: Using lambda CODE import operator students = {'Shweta':25,'Andy':30,'Maddy':3} v = max(students.items(),key=lambda x:x[1])[0] print (v) You can use any of these methods and you will get the same output. I hope you enjoyed learning this co...

It is quite common to use size() in Python. size() function gives you a total number of elements. Now, if it is that easy and straight forward, then why am I writing about it? Isn't it? Well, calculating the size or getting the output of the size() function is very straight forward, but when it comes to labeling this value, things become more complicated. Let's understand this with the help of an example. Input Data Here is how our sample data looks like. It is in the form of CSV: Scenario Explained The idea is to group data based on 2 columns named 'type_school' and 'interest' and then show their item count in a separate column. Here is the sample code to achieve this: import pandas as pd df = pd . read_csv ( 'data.csv' ) data = df . groupby ( [ 'type_school' , 'interest' ] ) data [ 'size' ] = data . size ( ) print ( data ) Python Copy The above code looks all good but you will end up seeing an error in it's execu...