Working on a data visualization project for a retail company, I had to create weekly sales charts using Python. The client wanted the charts in PNG format so they could easily include them in PowerPoint presentations and reports. If you’ve ever used Matplotlib in Python, you probably know how easy it is to display charts … Read more >>
I’ve realized that checking for a directory’s existence is one of those tasks you do almost every day. Whether I am setting up a new logging folder for a financial app in New York or verifying data paths for a California-based startup, I always need a reliable way to handle file systems. In this tutorial, … Read more >>
Putting a Matplotlib legend outside the plot takes two things: a figure made with layout="constrained", and fig.legend(loc="outside right upper"). The layout engine then shrinks the plot to make room, so nothing gets cut off: Most tutorials still teach the older bbox_to_anchor trick, which works but tends to crop the legend. I’ll show both and measure … Read more >>
Saving a pandas DataFrame to CSV takes one call: df.to_csv("sales.csv", index=False). The index=False part is the one people forget, and it’s the reason so many CSV files grow a mystery first column: I’ll also cover overwriting versus appending, number and date formats, Excel encoding and a Windows quirk that adds blank rows. The output comes … Read more >>
An empty array in Python is almost always just an empty list: prices = []. Python has no built-in array type you have to declare first, so a pair of square brackets is the whole answer for most code: When you need typed numbers or math on whole arrays, the array module and NumPy step … Read more >>
In Python, a new line is the \n character. Put it anywhere inside a string and everything after it starts on the next line when you print it: Below I cover the /n mix-up, a Windows path that breaks by itself, joining lists, triple quotes and writing files. The screenshots are real runs on Python … Read more >>
In this tutorial, I will explain how to parse a string in Python. As a data scientist working for a marketing analytics firm in New York, I recently worked on a project analyzing customer reviews to identify trends and insights. I needed to parse these strings and separate the data into structured fields to extract … Read more >>
In this tutorial, I will explain how to find the last occurrence of a substring in a string using Python. As a software developer working on a text processing tool for a legal firm, I needed to extract the last reference to a specific clause in lengthy contract documents. I researched more about this topic, … Read more >>
By default, when you convert a string to a float in Python, it may display many digits after the decimal point. However, in real-world scenarios like financial calculations or reports, you often need to show numbers with exactly two decimal places. In this article, I will explain some Python built-in methods to perform the conversion … Read more >>
Recently, I worked on a data analysis project for a US retail chain, where I needed to process thousands of sales records. The dates were stored as strings in various formats, which made analysis nearly impossible without proper conversion. The issue is that Python can’t directly perform date calculations on string representations of dates. We … Read more >>