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Posts Tagged ‘shell’

Python from command line

September 18, 2013 Leave a comment

Problem
You want to calculate something with Python quickly, from the command line. You might even want to use Python in a bash script to produce some result.

Solution

$ python -c "print 2*3"
6

Storing the result in a variable:

$ X=`python -c "print 2*3"`
$ echo $X
6

Thanks to Tajti A. for the tip.

Categories: python Tags: , , ,

call python in a shell script

March 5, 2012 Leave a comment

Problem
Floating point arithmetic in bash is problematic, expr supports integers only for instance.

Solution
Not an optimal solution but it works:

$ python -c "print 5.5*3"
16.5

$ num=`python -c "print 5.5*3"`
$ echo $num
16.5
Categories: python Tags: ,

IPython, an enhanced Python shell

March 19, 2011 Leave a comment

IPython is an interactive shell for the Python programming language that offers enhanced introspection, additional shell syntax, syntax highlighting, tab completion and rich history. It is a component of the SciPy package.” (source)

Links:

In the book Python for Unix and Linux System Administration, there is a long chapter (Ch. 2) dedicated to IPython!

Installation and usage
Install it via apt-get:

sudo apt-get install ipython

I made the alias “ip” for the command “ipython”. Note that there is a command “ip” for manipulating routing and tunnels that the alias will hide, but it’s not likely I’ll ever use that command.

alias ip='ipython'

The config file of IPython is located at ~/.ipython/ipy_user_conf.py.

Categories: python Tags: , ,