ITDA - Western Technical College

210 bookmarks
Newest
Modern Pandas (Part 1)
Modern Pandas (Part 1)
This is part 1 in my series on writing modern idiomatic pandas. Modern Pandas Method Chaining Indexes Fast Pandas Tidy Data Visualization Time Series Scaling Effective Pandas Introduction This series is about how to make effective use of pandas, a data analysis library for the Python programming language. It’s targeted at an intermediate level: people who have some experience with pandas, but are looking to improve. Prior Art There are many great resources for learning pandas; this is not one of them. For beginners, I typically recommend Greg Reda’s 3-part introduction, especially if they’re familiar with SQL. Of course, there’s the pandas documentation itself. I gave a talk at PyData Seattle targeted as an introduction if you prefer video form. Wes McKinney’s Python for Data Analysis is still the goto book (and is also a really good introduction to NumPy as well). Jake VanderPlas’s Python Data Science Handbook, in early release, is great too. Kevin Markham has a video series for beginners learning pandas.
·tomaugspurger.net·
Modern Pandas (Part 1)
Using Joins and Group Bys the right way for data warehousing
Using Joins and Group Bys the right way for data warehousing
Joins represent the denormalization of data to create dimensions and add dimension attributes to fact tables for reporting. Group bys enable the creation of metrics that determine how your data is used to make decisions. If you have wondered Why do your joins often end up in a dense block that's hard to pick apart. Why are people running nearly identical queries with only different join combinations. How to avoid losing data when performing joins How group bys have been used to mask underlying data modeling issues Why a group by all is considered a red flag Then this post is for you. In this post, we will cover how to use joins and group bys, as well as what to look out for when using them. By the end of this post, you will know what to watch out for when you perform joins or group bys.
·startdataengineering.com·
Using Joins and Group Bys the right way for data warehousing
All the secrets of SUMMARIZE - SQLBI
All the secrets of SUMMARIZE - SQLBI
SUMMARIZE is a very powerful and very complex function to use. This article describes its internal behavior, and provides guidance on how to use it. If you
·sqlbi.com·
All the secrets of SUMMARIZE - SQLBI
Understanding Context Transition - SQLBI
Understanding Context Transition - SQLBI
The context transition in DAX is the transformation of row contexts into an equivalent filter context performed by CALCULATE and CALCULATETABLE. Managing th
·sqlbi.com·
Understanding Context Transition - SQLBI