In this article I am planning to give an answer of the following two questions: What is a closure? A closure is a function, inheriting variables from enclosing environment. Operationally, a closure is a record storing a function together with…
Author: Vitosh
Python – Abstract Methods and Abstract Class – Live Coding Video
Abstract class and abstract methods are one of the pillars of Object Oriented Programming. In Python, an abstract class is a class, inheriting from Abstract Base Classes (ABC) library. And an abstract method is a method of this class, which…
Python – Permutations and Combinations Made Easy with Itertools
Long time ago, various people, including me, were trying to make permutations and combinations with nested loops and various other “heavy” structures. Anyway, in Python there is a library, which does this for us and sets the end of the…
Python – Defining Classes and Methods with Python – LiveCoding Video
Today I have decided to check whether I can pass the first homework from SoftUni OOP with Python, through a live coding session. I have not read the problem before the video, thus I may say it took me exactly…
Python – The End of the Matrix Wandering
Ok. This article is for all the people, who have written code like this one:
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1 2 3 4 |
if direction == "left" then if column > 0 then: new_row = current_row new_col = current_col - 1 |
When they were solving a problem like this one: You know who you are. You are probably thinking what is wrong with it? After…
Python – Making Maps with Cartopy
Cartopy is a Python package designed for geospatial data processing in order to produce maps and other geospatial data analyses. Making a map with Python and Cartopy is actually easier than you might think, but still it has its own…
Python – Bayes’ theorem – Drug testing example. 99% is not enough!
The Bayes’ theorem is interesting, as far as it is both quite challenging to understand and shocking once you really realize the simplicity of the numbers behind it. It describes the probability of an event, based on prior knowledge of conditions that…
Python – Linear Regression
In 2013 and 2014 (wow, already 7 years ago!) I wrote two articles about linear regression with Excel. Now, I am getting more and more interested in Python, thus I guess it would be interesting to remake the article into…
Tagged with: linear regression, plotting, plotting both predicted and real values, prediction, Python
Python – Building New Columns in a Dataframe, Based on Other Columns
Working with python, pandas and dataframes is quite challenging even for experienced Excel & VBA developer, as I love to consider myself for one. Thus, today I was fighting for quite some time to add new columns to a dataframe,…
Tagged with: adding columns, based on columns, based on rows, computating column, dataframe, offset, Python, shift, shifting column
Python – *args, **kwargs and the normal ones (arg)
The good, the bad and the ugly is a famous western. In Python, “the ugly” is probably the **kwargs, as far as it has two stars before it. Anyhow, the idea of *args, **kwargs and arg is simply to pass arguments.…
Python – List Comprehension
List comprehension in Python is creation of lists from iterables and other lists, following a condition. It is lightning fast and it looks nice, because it is a 1 liner. In this article, I will show a few examples of…
Tagged with: conditions, dictionary comprehension, examples, list comprehension, matrix comprehension, Python
Python – What is the idea of “-1” in numpy reshape?
Today I was “fighting” with the numpy reshape function and I found something strange like matrix.reshape(1, -1). Thus, I have researched quite some time and I found, that the -1 is actually a placeholder for python to change the dimensions of…
Python – How to write string into a matrix. Printing a matrix.
Writing string into a matrix seems like a non-interesting and somehow trivial task. Anyway, manipulating with matrices and strings in Python is actually somehow interesting, thus I have decided to present a small algorithmic challenge. The task is pretty much…
VBA – String.Format or how to put variables in a string
C#, Python, Java and all the other “fancy” languages have a built-in method, which writes variables into a string. VBA does not have one. Depending on why do we need it, and if we can guarantee that no injection would…
VBA – Make a list of the formula errors in an Excel
Errors in Excel are different – from “Division by Zero” (#Div/0) and #Name to #REF! and #Num. There are lots of ways to summarize these into some kind of report and in the current article I will show the VBA…
VBA Boilerplate
Dreaming of having a boilerplate for Excel VBA project? Or you have other dreams, which are more normal? Well, I cannot help in the latter case, but if you want a boilerplate for VBA – here it is!
C# – Build a .NET Standard library with Visual C# – Video
Following the Microsoft tutorial for building a .Net Standard library with Visual Basic from here, I have decided to make a video for .Net Standard library with C#. Pretty much, it is one and the same. The library contains one…
Writing data from text file to Excel cells
There are quite a few methods for writing data from a text file to Excel. The main are the following: Through a Query Table Through opening the text file and Reading and writing line by line Reading the text file,…
Tagged with: Data Transfer, from text file, LoopThroughLines, QueryTables.Add, to excel cells, Writing data
Python – UnitTests in Jupyter Notebook
Unit testing is the “sweet” part of the programming – once you have tested “all the things”, you feel that the code you have submitted somewhere is actually valid and somehow it works. Furthermore, it allows you to nicely brag…
Book Review – Stephen Wolfram – Adventures of Computational Explorer
Some time ago, I have received the book of Stephen Wolfram – Adventures of Computational Explorer for a review. Stephen is the guy behind WolframAlpha – https://www.wolframalpha.com/, a PhD in physics before his 21. birthday, considered a prodigy by some…
VBA – Extracting financial data from a website in table format
Although there are plenty of other tools for extracting data from a website (take a look at Beautiful Soup), VBA is somehow good, because … well, because it is somehow challenging to do it every time. Yesterday, I answered a…
Tagged with: Data scraping, from cell, from internet, reading data, reading from table, remove empty elements from array, VBA
Python – Statsmodels Example – Video
Statsmodels is a nice statistics library in Python, which eases the data processing and analysis with Python. The library is available here – statsmodels.org and on its official web site the installation guide is always up to date. In the…
Excel – How to build magic square with VBA, following Python Mod Mathematics
Some 4 years ago I wrote an article for calculating magic square with python. What the article did was actually checking whether the square is magic, and not calculating a new one. This one is going to show how these…
Python – Plotting DataFrame and Working with Pandas – Video
Working with Pandas is like working with Excel on steroids – it can really do a lot of things fast, but somehow doing the easy things get complicated. In this video and article tutorial I am presenting loading data to…
Python – Platforms Jumping – CodeForces
Greedy algorithm is described as an algorithm that follows the problem-solving heuristic of making the locally optimal choice at each stage with the intent of finding a global optimum. Thus, it is always interesting to find a problem, which can…
Python Slice Notation
Python Slice Notation is somehow easy and tough in the same way. Lately, I was doing some competitive programming with Python and I have decided to write a summary of the slice notation, thus there is always a place for…
Python – Binary String Minimizing Problem – CodeForces
Codeforces has introduced a third division in their competitions. Initially I though this is the place to go for “easy” stuff, as far as some of the 2nd division problems require some advanced algorithms, like combinations of graphs and months…
Find all list (li) elements in a special position of a web site
So, my idea was to obtain all the elements, tagged with “li” from here – vitoshacademy.com/all, using BeautifulSoup4 and Python. Initially, I thought about running a simple soup.findAll("li") , but it also added the text from the menus, which were…
Scraping a web site up to the N-th level with Python
Scraping data from a web site has always been a pleasure with Python. If you come from the VBA world, the BeautifulSoup4 is indeed beautiful! I have been scraping a web site with python before, but now as I have…
Dynamic dropdown list in Excel VBA with variables
Dropdown lists in Excel usually are built from a range or from a variable list. Dropdown list from Excel Range Thus, building a dynamic dropdown list may include building a dynamic range, with undeclared end. Thus, let’s imagine that the…
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