50+ Data Science, Machine Learning Cheat Sheets, updated
Gear up to speed and have concepts and commands handy in Data Science, Data Mining, and Machine learning algorithms with these cheat sheets covering R, Python, Django, MySQL, SQL, Hadoop, Apache Spark, Matlab, and Java.
This post updates a previous very popular post 50+ Data Science, Machine Learning Cheat Sheets by Bhavya Geethika. If we missed some popular cheat sheets, add them in the comments below.
Data science is a multidisciplinary field. Thus, there are thousands of packages and hundreds of programming functions out there in the data science world! An aspiring data enthusiast need not know all. A cheat sheet or reference card is a compilation of mostly used commands to help you learn that language’s syntax at a faster rate. Here are the most important ones that have been brainstormed and captured in a few compact pages.
Mastering Data science involves understanding of statistics, mathematics, programming knowledge especially in R, Python & SQL and then deploying a combination of all these to derive insights using the business understanding & a human instinct—that drives decisions.
Here are the cheat sheets by category:
Cheat sheets for Python:
Python is a popular choice for beginners, yet still powerful enough to back some of the world’s most popular products and applications. It's design makes the programming experience feel almost as natural as writing in English. Python basics or Python Debugger cheat sheets for beginners covers important syntax to get started. Communityprovided libraries such as numpy, scipy, scikit and pandas are highly relied on and the NumPy/SciPy/Pandas Cheat Sheet provides a quick refresher to these.
 Python 2.7 Quick Reference Sheet
 Python Cheat Sheet by DaveChild via cheatography.com
 Python Basics Reference sheet via cogsci.rpi.edu
 Python Debugger Cheatsheet
 NumPy / SciPy / Pandas Cheat Sheet
 OverAPI.com Python cheatsheet
 Python 3 Cheat Sheet by Laurent Pointal
 Python Language & Syntax Cheat Sheet
 DataCamp’s Python Pandas cheat sheet
Cheat sheets for R:
The R's ecosystem has been expanding so much that a lot of referencing is needed. The R Reference Card covers most of the R world in few pages. The Rstudio has also published a series of cheat sheets to make it easier for the R community. The data visualization with ggplot2 seems to be a favorite as it helps when you are working on creating graphs of your results.
At cran.rproject.org:
 R functions for Regression Analysis
 R short reference Card
 R functions for Time series Analysis
 R Reference Card for Data Mining
At Rstudio.com:
 Interactive Web Apps cheatsheet
 Data Visualisation with ggplot2 cheatsheet
 Package Development with devtools cheatsheet
 Data wrangling cheat sheet
 R markdown cheatsheet, part 2
Others:
 R Data Management cheatsheet
 R Cheatsheet for graphical parameters
 R Cheat Sheet
 DataCamp’s Data Analysis the data.table way
Cheat sheets for MySQL & SQL:
For a data scientist basics of SQL are as important as any other language as well. Both PIG and Hive Query Language are closely associated with SQL the original Structured Query Language. SQL cheatsheets provide a 5 minute quick guide to learning it and then you may explore Hive & MySQL!
 MySQL cheat sheet by Dave Child
 SQL cheat sheet
 SQL in one page
 MySQL reference guide
 Visual SQL joins
 SQL for dummies cheat sheet
Cheat sheets for Spark, Scala, Java:
Apache Spark is an engine for largescale data processing. For certain applications, such as iterative machine learning, Spark can be up to 100x faster than Hadoop (using MapReduce). The essentials of Apache Spark cheatsheet explains its place in the big data ecosystem, walks through setup and creation of a basic Spark application, and explains commonly used actions and operations.
 Dzone.com’s Apache Spark reference card
 Scala cheatsheets 1
 Scala cheatsheets 2
 DZone.com’s Scala reference card
 Spark cheatsheet on github
 Openkd.info’s Scala on Spark cheat sheet
 Java cheat sheet at MIT.edu
 Cheat Sheets for Java at Princeton.edu
Cheat sheets for Hadoop & Hive:
Hadoop emerged as an untraditional tool to solve what was thought to be unsolvable by providing an open source software framework for the parallel processing of massive amounts of data. Explore the Hadoop cheatsheets to find out Useful commands when using Hadoop on the command line. A combination of SQL & Hive functions is another one to check out.
 Hadoop for Dummies cheatsheet
 Getting Started Apache Hadoop Reference Card
 Hadoop Command Line cheatsheet
 Working with HDFS from the command line  Hadoop Cheat sheet
 Hive Function cheatsheet
 SQL to Hive cheat sheet
Cheat sheets for web application framework Django:
Django is a free and open source web application framework, written in Python. If you are new to Django, you can go over these cheatsheets and brainstorm quick concepts and dive in each one to a deeper level.
 Django cheat sheet v.1
 Django cheat sheet part 1, part 2, part 3, part 4
 Django Reference Cheatsheet
 Django Quick start guide & Cheatsheet
Cheat sheets for Machine learning:
We often find ourselves spending time thinking which algorithm is best? And then go back to our big books for reference! These cheat sheets gives an idea about both the nature of your data and the problem you're working to address, and then suggests an algorithm for you to try.
 Machine Learning cheat sheet at scikitlearn.org
 ScikitLearn Cheat Sheet: Python Machine Learning from yhat (added by GP)
 Patterns for Predictive Learning cheat sheet at Dzone.com
 Machine learning algorithm cheat sheet for Microsoft Azure
 Equations and tricks Machine Learning cheat sheet at Github.com
 Supervised learning superstitions cheatsheet at Github.com
 Ten machine learning algorithms in R cheat sheet
Cheat sheets for Matlab/Octave
MATLAB (MATrix LABoratory) was developed by MathWorks in 1984. Matlab d has been the most popular language for numeric computation used in academia. It is suitable for tackling basically every possible science and engineering task with several highly optimized toolboxes. MATLAB is not an opensourced tool however there is an alternative free GNU Octave reimplementation that follows the same syntactic rules so that most of coding is compatible to MATLAB.
Cheat sheets for Cross Reference between languages
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