Tab completion, which helps you find a command

History mechanism

Inline editing

Ability to call external Python scripts with %run

Access to system commands

The pylab switch

Access to the Python debugger and profiler

The pylab switch: The pylab switch automatically imports all the Scipy, NumPy, and matplotlib packages. Without this switch, we would have to import these packages ourselves.

All we need to do is enter the following instruction on the command line:

$ ipython -pylab
Type "copyright", "credits" or "license" for more information.

IPython 2.0.0-dev -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

Welcome to pylab, a matplotlib-based Python environment [backend: MacOSX].
For more information, type 'help(pylab)'.

In [1]: quit()

Saving a session: We might want to be able to go back to our experiments. In IPython, it is easy to save a session for later use, with the following command:

In [1]: %logstart
Activating auto-logging. Current session state plus future input saved.
Filename       : ipython_log.py
Mode           : rotate
Output logging : False
Raw input log  : False
Timestamping   : False
State          : active

Logging can be switched off as follows:

In [9]: %logoff
Switching logging OFF

Executing system shell command: Execute a system shell command in the default IPython profile by prefixing the command with the ! symbol. For instance, the following input will get the current date:

In [1]: !date

In fact, any line prefixed with ! is sent to the system shell. Also, we can store the command output as shown here:

In [2]: thedate = !date
In [3]: thedate

Displaying history: We can show the history of commands with the %hist command, for example:

In [1]: a = 2 + 2

In [2]: a
Out[2]: 4

In [3]: %hist
a = 2 + 2
a
%hist

This is a common feature in Command Line Interface (CLI) environments. We can also search through the history with the -g switch as follows:

In [5]: %hist -g a = 2
    1: a = 2 + 2