Programming Articles - Page 1759 of 3366

In this article we are going to see how to count the numbers of pairs of numbers which have an exact difference equal to k. The given numbers are in form of a list and we supply the value of k to the program.Using for LoopIn this approach we design two for loops, one inside another. The outer for loop keeps track of visiting each element of the given list. The inner for loop keeps comparing each of the remaining elements with the element of the outer loop and increase the value of the count variable if it matches the ... Read More

Pandas is a famous python library that Is extensively used for data processing and analysis in python. In this article we will see how to use the .iloc method which is used for reading selective data from python by filtering both rows and columns from the dataframe.iloc method processes data by using integer based indexes which may or may not be part of the original data set. The first row is assigned index 0 and second and index 1 and so on. Similarly, the first column is index 0 and second is index 1 and so on.The Data SetBelow is ... Read More

Sometimes we may have a need to refine a given list by eliminating the duplicate elements in it. This can be achieved by using a combination of various methods available in python standard library.with set and splitThe split method can be used to segregate the elements for duplicate checking and the set method is used to store the unique elements from the segregated list elements.Example# initializing list listA = [ 'xy-xy', 'pq-qr', 'xp-xp-xp', 'dd-ee'] print("Given list : ", listA) # using set() and split() res = [set(sub.split('-')) for sub in listA] # Result print("List after duplicate removal ... Read More

The dir() function returns list of the attributes and methods of any object like functions , modules, strings, lists, dictionaries etc. In this article we will see how to use the dir() in different ways in a program and for different requirements.Only dir()When we print the value of the dir() without importing any other module into the program, we get the list of methods and attributes that are available as part of the standard library that is available when a python program is initialized.ExamplePrint(dir())OutputRunning the above code gives us the following result −['__annotations__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', ... Read More

Multiplying two lists in python can be a necessity in many data analysis calculations. In this article we will see how to multiply the elements of a list of lists also called a nested list with another list.Using LoopsIn this approach we design tow for loops, one inside another. The outer loop keeps track of number of elements in the list and the inner loop keeps track of each element inside the nested list. We use the * operator to multiply the elements of the second list with respective elements of the nested list.Example Live DemolistA = [[2, 11, 5], [3, ... Read More

Sometimes when creating a matrix using python we may need to control how many times a given element is repeated in the resulting matrix. In this articled we will see how to create a matrix with required number of elements when the elements are given as a list.Using zipWe declare a list with elements to be used in the matrix. Then we declare another list which will hold the number of occurrences of the element in the matrix. Using the zip function we can create the resulting matrix which will involve a for loop to organize the elements.Example Live DemolistA = ... Read More

Pandas is a very widely used python library for data processing and data analysis. In this article we will see how we we can create pandas dataframe from given python dictionaries and lists.From dictionary with listsDictionaries are key value pairs. If we take a python dictionary which has key and a list as a value then we can directly use the DataFrame method on the given dictionary to create the pandas data frame.Example Live Demoimport pandas as pd # Dictionary for Exam Schedule Exam_Schedule = { 'Exam Day': ['Mon', 'Tue', 'Wed', 'Thu', 'Fri'], 'Exam Subject': ['Chemisry', 'Physics', 'Maths', 'English', 'Biology'], ... Read More

Pandas creates data frames to process the data in a python program. In this article we will see how we can add a new column to an existing dataframe based on certain conditions.The Given Data FrameBelow is the given pandas DataFrame to which we will add the additional columns. It describes the Days and Subjects of an examination.Example Live Demoimport pandas as pd # Lists for Exam subjects and Days Days = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri'] Sub = ['Chemisry', 'Physics', 'Maths', 'English', 'Biology'] # Dictionary for Exam Schedule Exam_Subjects = {'Exam Day': Days,           ... Read More

Python’s wide availability of libraries enables it to interact with Microsoft excel which is a very widely used data processing tool. In this article we will see how we can use the module named xlsxwriter to create and write into a excel file. It cannot write into existing excel file.Writing to Each CellWe can write to each cell of an excel sheet by writing to the name of the cell. In the below example we create a workbook and then ass a worksheet to it. Finally write to the cells of the worksheet using the write() method.Exampleimport xlsxwriter # ... Read More

The Dataframe in pandas can be created using various options. One of the option is to take a dictionary and convert it to a Dataframe. In this article we will see how to take three lists of equal length and convert them to a pandas dataframe using a python dictionary.Uisng Lists and DictionaryIn this approach we have the lists declared individually. Then each of them is used as a value for the appropriate key inside a dictionary definition. Finally the pandas method called pd.Dataframe is applied to the dictionary.Example Live Demoimport pandas as pd # Lists for Exam schedule Days ... Read More