Initiating ipython shell in terminal ipython
Initiating Jupyter notebook in terminal jupyter notebook
help(len) = len?
To get the source code len??
Both of this even works for the functions that you have created.
Tab completion is awesome. len.<tab>
Tab completion is great in conjunction with from pandas import <tab> and import <tab> to list out the objects and libraries.
* with ? for wildcard matching. *warning? and str.*find*?
ctrl + u copy from beginning, ctrl + y paste
ctrl + p previous command in history, ctrl + r history command
ctrl + l clear, ctrl + d Exit
%paste paste without indentation problem
%run test.py run a .py file in the same folder, and functions of that file is now available in the shell, and you can call them.
%timeit for single line execution, and %%timeit for multiline codes.
%magic and %lsmagic to get a list of magic functions.
Everything you input is stored in In which is a list (Input number is index number) and Everything you output is stored in Out as a dictionary (Output number is Key).
For easy access to output use print(_), 1 underscore is the last one, 2 underscore as in print(__) for the 2nd last Out or output result.
Out[2] = _2
for not displaying an output end the statement with a semicolon. math.e;
%history -n 1-4 return history input, -n for index number, 1-4 for limiting the return statement.
shell commands work in ipython by prefixing them with !, i.e. !ls
We can also assign variables to the output of this ipython shell commands i.e. files = !ls, which returns a special kind of list.
You can also use python variables as shell variables by using {varname} i.e. !echo {message}
You can cd by magic command %cd or simply cd. This works for every shell command.
%xmode limits the exception (/error) message. %xmode takes a single argument of the three, Plain(less information), Context(Default), and Verbose(More information). i.e. %xmode Plain.
python’s standard debugger pdb, and ipython's is ipdb. We enter into debugging with %debug. Then start giving commands (print, type etc.) to check, and quit.
To run a file in debugging mode %run -d test.py
In the debugger help. help <specific command>.
This summary is based on the book Python Data Science Handbook by Jake VanderPlas
