Python Articles - Page 620 of 829

How to perform Calculations with Dictionaries in Python?

Kiran P
Updated on 09-Nov-2020 10:41:18

2K+ Views

ProblemYou want to perform various calculations (e.g., minimum value, maximum value, sorting, etc.) on a dictionary of data.Solution.We will create a dictionary with tennis players and their grandslam titles.PlayerTitles = {    'Federer': 20,    'Nadal': 20,    'Djokovic': 17,    'Murray': 3,    'Theim' : 1,    'Zverev': 0 }1.We have a dictionary with player names and the grandslam titles won by each player. Now let us try to find out the player with least number of titles#type(PlayerTitles) print(f"Output *** The minimum value in the dictionary is {min(PlayerTitles)} ")Output*** The minimum value in the dictionary is Djokovic2. This is ... Read More

How to compare two DataFrames in Python Pandas with missing values

Kiran P
Updated on 09-Nov-2020 10:36:56

2K+ Views

IntroductionPandas uses the NumPy NaN (np.nan) object to represent a missing value. This Numpy NaN value has some interesting mathematical properties. For example, it is not equal to itself. However, Python None object evaluates as True when compared to itself.How to do it..Let us see some examples to understand how np.nan behaves.import pandas as pd import numpy as np # Python None Object compared against self. print(f"Output *** {None == None} ")Output*** True# Numpy nan compared against self. print(f"Output *** {np.nan == np.nan} ")Output*** False# Is nan > 10 or 1000 ? print(f"Output *** {np.nan > ... Read More

Program to find next board position after sliding the given direction once in Python

Arnab Chakraborty
Updated on 09-Nov-2020 10:36:31

218 Views

Suppose we have a 2048 game board representing the initial board and a string direction representing the swipe direction, we have to find the next board state. As we know in the 2048 game, we are given a 4 x 4 board of numbers (some of them are empty, represented in here with 0) which we can swipe in any of the 4 directions ("U", "D", "L", or "R"). When we swipe, all the numbers move in that direction as far as possible and identical adjacent numbers are added up exactly once.So, if the input is likedirection = "L", then ... Read More

How to use the Subprocess Module in Python?

Kiran P
Updated on 09-Nov-2020 10:29:33

1K+ Views

Understanding Process -When you code and execute a program on Windows, MAC or Linux, your Operating System creates a process(single).It uses system resources like CPU, RAM, Disk space and also data structures in the operating system’s kernel. A process is isolated from other processes—it can’t see what other processes are doing or interfere with them.Note: This code has to be run on Linux like sytems. When executed on windows might throw exceptions.Goals of Operating System -The main twin goals of OS are to spread the work of the process fairly and be responsive to the user. These are acheived by ... Read More

How to process iterators in parallel using ZIP

Kiran P
Updated on 09-Nov-2020 10:27:45

398 Views

IntroductionList comprehensions make it easy to take a source list and get a derived list by applying an expression. For example, say that I want to multiply each element in a list with 5. Here, I do this by using a simple for loop.a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] multiply_by_5 = [] for x in a: multiply_by_5.append(x*5) print(f"Output *** {multiply_by_5}")Output*** [5, 10, 15, 20, 25, 30, 35, 40, 45, 50]With a list comprehension, I can achieve the same outcome by specifying the expression and the input sequence to loop over.# List comprehension multiply_by_5 ... Read More

How to process excel files data in chunks with Python?

Kiran P
Updated on 09-Nov-2020 10:18:17

3K+ Views

IntroductionIt seems that the world is ruled by Excel. I've been surprised in my data engineering work to see how many of my colleagues are using Excel as a critical tool for making decisions. While I'm not a big fan of MS Office and their excel spread sheets, i will still show you a neat trick to handle large excel spread sheets effectively.How to do it..Before we jump into the program directly, let us understand few basics on dealing excel spreadsheets with Pandas.1. Installation. Go ahead and install openpyxl and xlwt. If you are unsure if it is installed or ... Read More

How to Parse HTML pages to fetch HTML tables with Python?

Kiran P
Updated on 09-Nov-2020 10:04:02

881 Views

ProblemYou need to extract the HTML tables from a web page.IntroductionThe internet, and the World Wide Web (WWW), is the most prominent source of information today. There is so much information out there, it is just very hard to choose the content from so many options. Most of that information is retrievable through HTTP.But we can also perform these operations programmatically to retrieve and process information automatically.Python allows us to do this using its standard library an HTTP client, but the requests module helps in obtaining web pages information very easy.In this post, we will see how to parse through ... Read More

How to find and filter Duplicate rows in Pandas ?

Kiran P
Updated on 10-Nov-2020 09:38:28

7K+ Views

Sometimes during our data analysis, we need to look at the duplicate rows to understand more about our data rather than dropping them straight away.Luckily, in pandas we have few methods to play with the duplicates..duplciated()This method allows us to extract duplicate rows in a DataFrame. We will use a new dataset with duplicates. I have downloaded the Hr Dataset from link.import pandas as pd import numpy as np # Import HR Dataset with certain columns df = pd.read_csv("https://raw.githubusercontent.com/sasankac/TestDataSet/master/HRDataset.csv", usecols = ("Employee_Name""PerformanceScore", "Position", "CitizenDesc")) #Sort the values on employee name and make it permanent df.sort_values("Employee_Name"inplace = True) df.head(3)Employee_NamePositionCitizenDescPerformanceScore0AdinolfiProduction ... Read More

How to select a Subset Of Data Using lexicographical slicingin Python Pandas?

Kiran P
Updated on 10-Nov-2020 09:34:45

366 Views

IntroductionPandas have a dual selection capability to select the subset of data using the Index position or by using the Index labels. Inthis post, I will show you how to "Select a Subset Of Data Using lexicographical slicing".Google is full of datasets. Search for movies dataset in kaggle.com. This post uses the movies data set from kaggle.How to do it1. Import the movies dataset with only the columns required for this example.import pandas as pd import numpy as np movies = pd.read_csv("https://raw.githubusercontent.com/sasankac/TestDataSet/master/movies_data.csv", index_col="title", usecols=["title", "budget", "vote_average", "vote_count"]) movies.sample(n=5)titlebudgetvote_averagevote_countLittle Voice06.661Grown Ups 2800000005.81155The Best Years of Our Lives21000007.6143Tusk28000005.1366Operation Chromite05.8292. I always recommend ... Read More

How to select subset of data with Index Labels in Python Pandas?

Kiran P
Updated on 10-Nov-2020 06:32:47

2K+ Views

IntroductionPandas have a dual selection capability to select the subset of data using the Index position or by using the Index labels. Inthis post, I will show you how to “Select a Subset Of Data Using Index Labels” using the index label.Remember, Python dictionaries and lists are built-in data structures that select their data either by using the index label or byindex position. A dictionary’s key must be a string, integer, or tuple while a List must either use integers (the position) or sliceobjects for selection.Pandas have .loc and.iloc attributes available to perform index operations in their own unique ways. ... Read More

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