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Pandas is a very widely used python library for data cleansing, data analysis etc. In this article we will see how we can use the query method to fetch specific data from a given data set. We can have both single and multiple conditions inside a query.Reading the dataLet’s first read the data into a pandas data frame using the pandas library. The below program just does that.Exampleimport pandas as pd # Reading data frame from csv file data = pd.read_csv("D:\heart.csv") print(data)OutputRunning the above code gives us the following result −Query with single conditionNext we see how we ... Read More
Hubs are networking devices operating at a physical layer of the OSI model that are used to connect multiple devices in a network. They are generally used to connect computers in a LAN.A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination device or not.Features of HubsA hub operates in the physical layer of the OSI model.A hub cannot filter ... Read More
As part of data cleansing activities, we may sometimes need to take out the integers present in a list. In this article we will have an array containing both floats and integers. We will remove the integers from the array and print out the floats.With astypeThe astype function will be used to find if an element from the array is an integer or not. Accordingly we will decide to keep or remove the element from the array and store it in the result set.Example Live Demoimport numpy as np # initialising array A_array = np.array([3.2, 5.5, 2.0, 4.1, 5]) ... Read More
Sometimes in a Python dictionary we may need to to filter out certain keys of the dictionary based on certain criteria. In this article we will see how to filter out keys from Python dictionary.With for and inIn this approach we put the values of the keys to be filtered in a list. Then iterate through each element of the list and check for its presence in the given dictionary. We create a resulting dictionary containing these values which are found in the dictionary.Example Live DemodictA= {'Mon':'Phy', 'Tue':'chem', 'Wed':'Math', 'Thu':'Bio'} key_list = ['Tue', 'Thu'] print("Given Dictionary:", dictA) print("Keys for filter:", ... Read More
Both abs() and fabs() represent the mathematical functions which give us the absolute value of numbers. But there is a subtle difference between both of them which we can explore in the exmaples below.ExampleThe abs() functions returns the absolute value as an integer or floating point value depending on what value was supplied dot it. But the fabs) function will always return the value as floating point irrespective of whether an integer or a floating point was supplied to it as a parameter. Live Demoimport math n = -23 print(abs(n)) print(math.fabs(n)) n = 21.4 print(abs(n)) print(math.fabs(n)) n = ... Read More
The print() function in python always creates a newline. But there is also a parameter for this function which can put other characters instead of new line at the end. In this article we will explore various options for this parameter.ExampleIn the below example we see various ways we can assign values to the end parameter and see the result from it. Live Demoprint("Welcome to ") print("Tutorialspoint") print("Welcome to ", end = ' ') print("Tutorialspoint") print("emailid", end='@') print("tutorialspoint.com")OutputRunning the above code gives us the following result −Welcome to Tutorialspoint Welcome to Tutorialspoint emailid@tutorialspoint.comRead More
Two python dictionaries may contain some common keys between them. In this article we will find how to get the difference in the keys present in two given dictionaries.With setHere we take two dictionaries and apply set function to them. Then we subtract the two sets to get the difference. We do it both ways, by subtracting second dictionary from first and next subtracting first dictionary form second. Those keys which are not common are listed in the result set.Example Live DemodictA = {'1': 'Mon', '2': 'Tue', '3': 'Wed'} print("1st Distionary:", dictA) dictB = {'3': 'Wed', '4': 'Thu', '5':'Fri'} print("1st Distionary:", ... Read More
Suppose you are given a list but we want to convert it to dictionary. Dictionary elements hold two values are called key value pair, we will use in case of value. The elements of the list become keys and non will remain a placeholder.With dictThe dict() constructor creates a dictionary in Python. So we will use it to create a dictionary. The fromkeys method is used to create the dictionary elements.Example Live DemolistA = ["Mon", "Tue", "Wed", "Thu", "Fri"] print("Given list: ", listA) res = dict.fromkeys(listA) # New List print("The list of lists:", res)OutputRunning the above code gives us ... Read More
In this tutorial, we will be discussing a program to find maximum Sum Increasing Subsequence.For this we will be provided with an array containing N integers. Our task is to pick up elements from the array adding to the maximum sum such that the elements are in sorted orderExample Live Demo#include using namespace std; //returning the maximum sum int maxSumIS(int arr[], int n) { int i, j, max = 0; int msis[n]; for ( i = 0; i < n; i++ ) msis[i] = arr[i]; for ( i = 1; i < n; ... Read More
There may be a situation when we need to convert the elements in the list into a list in itself. In other words, create a list which is nested as its elements are also lists.Using iterationThis is the novel approach in which we take each element of the list and convert it to a format of lists. We use temporary list to achieve this. Finally all these elements which are converted to lists are group together to create the required list of lists.Example Live DemolistA = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri'] print("Given list:", listA) new_list = [] # Creating ... Read More