Magic commands in IPython


IPython is a integrated Python interface, and it introduces a set of magic commands which start with %. These magic commands are very handy when we use IPython. This post discusses several helpful magic commands.

%logstart and %logstop: These two commands can be used to switch on and off the logging mode in IPython. With %logon and logoff commands, the logging mode can be switched on and off when logging.

%paste: We often use IPython as a testing environment, so we want to paste a function written in an IDE to IPython. However, if we just use copy + paste, the format might become messy. Here comes %paste, which will perfectly reserve the indentations and other formats.

%run: If we write a python script in an IDE, and would like to test the whole script or just execute it, we can do this inside of IPython with the %run command.

Although IPython accepts the !python to execute a python script, but this magic command is much shorter. Remember [Laziness Impatience Hubris](http://c2.com/cgi/wiki?LazinessImpatienceHubris, right? Laziness is a virtue.

%save: This command can save logged IPython history to a file. The default destination is to the working directory.

%timeit: Sometime, we would like to compare the efficiency of different functions. Although Python’s time library might help, IPython provides a built-in solution for this problem. We can use %timeit to carry out the comparison. Suppose we have a function called my_function, we can test it as:

%timeit my_function

No parenthesis behind the function name.

Posted with : python, ipython

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