MATLAB:

• http://www.econ.ku.dk/pajhede/Cheatsheet.pdf

MATLAB Indexing:

• http://people.duke.edu/~jmp33/matlab/indexing_cheatsheet.pdf

Python:

• 2.7 - http://www.astro.up.pt/~sousasag/Python_For_Astronomers/Python_qr.pdf
• Part I - http://datasciencefree.com/python.pdf
• Part II - http://www.codeconquest.com/wp-content/uploads/Python-Cheat-Sheet-by-CodeConquestDOTcom.pdf
• Data Science - https://s3.amazonaws.com/../../PythonForDataScience.pdf

NumPy:

• http://mathesaurus.sourceforge.net/matlab-numpy.html
• https://www.dataquest.io/blog/images/cheat-sheets/numpy-cheat-sheet.pdf

Pandas:

• http://pandas.pydata.org/Pandas_Cheat_Sheet.pdf

Big-O Complexity:

• https://github.com/ro31337/bigoposter/raw/master/bigoposter.pdf

Probability:

• https://static1.squarespace.com/static/../../probability_cheatsheet.pdf

Statistics:

• http://web.mit.edu/~csvoss/Public/usabo/stats_handout.pdf

Mathematics:

• http://tutorial.math.lamar.edu/pdf/Calculus_Cheat_Sheet_All.pdf
• http://tutorial.math.lamar.edu/pdf/Algebra_Cheat_Sheet.pdf

PyQt:

• https://wiki.python.org/moin/JonathanGardnerPyQtTutorial

OpenCV:

• https://docs.opencv.org/2.4/opencv_cheatsheet.pdf

SciPy:

• https://s3.amazonaws.com/../../Python_SciPy_Cheat_Sheet_Linear_Algebra.pdf

Scikit-Learn:

• https://s3.amazonaws.com/../blog_assets/Scikit_Learn_Cheat_Sheet_Python.pdf

Matplotlib:

• https://s3.amazonaws.com/../blog_assets/Python_Matplotlib_Cheat_Sheet.pdf

Conda:

• https://conda.io/docs/_downloads/conda-cheatsheet.pdf

PyCharm:

• https://blog.jetbrains.com/pycharm/files/2010/07/PyCharm_Reference_Card.pdf

Android Studio:

• https://resources.jetbrains.com/storage/products/intellij-idea/docs/IntelliJIDEA_ReferenceCard.pdf

chmod:

• http://www.draac.com/chmodchart.html

HTML:

• https://websitesetup.org/HTML5-cheat-sheet.pdf

CSS:

• I prefer to use a source of reference. Referring to w3c and MDN is highly recommended for writing a clean and semantic code.

Capacitor Codes:

• http://www.synthrotek.com/wp-content/uploads/2012/08/Capacitor-Codes.pdf

TCP Ports:

• https://www.gasmi.net/tcp.php

Git:

• https://education.github.com/git-cheat-sheet-education.pdf

Atom Editor:

• https://d2wy8f7a9ursnm.cloudfront.net/atom-editor-cheat-sheet.pdf

VS Code:

• https://code.visualstudio.com/shortcuts/keyboard-shortcuts-windows.pdf

Spyder:

• http://e-callisto.org/cospar2018/SpyderKeyboardShortcutsEditor.pdf

Markdown:

• https://guides.github.com/pdfs/markdown-cheatsheet-online.pdf

Other places to swear by:

• https://learnxinyminutes.com/
• http://www.cheat-sheets.org/
• https://www.printfriendly.com/