PyMOTW: csv

The csv module is very useful for working with data exported from
spreadsheets and databases into text files. There is no well-defined
standard, so the csv module uses “dialects” to support parsing using
different parameters. Along with a generic reader and writer, the module
includes a dialect for working with Microsoft Excel.

Read more at pymotw.com: csv

PyMOTW: glob

Even though the glob API is very simple, the module packs a lot of
power. It is useful in any situation where your program needs to look
for a list of files on the filesystem with names matching a pattern. If
you need a list of filenames that all have a certain extension, prefix,
or any common string in the middle, use glob instead of writing code to
scan the directory contents yourself.

Read more at pymotw.com: glob

PyMOTW: atexit

The atexit module provides a simple interface to register
functions to be called when a program closes down normally. The
sys module also provides a hook, sys.exitfunc, but only one
function can be registered there. The atexit registry can be used
by multiple modules and libraries simultaneously.

Read more at pymotw.com: atexit

PyMOTW: subprocess

The subprocess module provides a consistent interface to creating and
working with additional processes. It offers a higher-level interface
than some of the other available modules, and is intended to replace
functions such as os.system, os.spawn*, os.popen*, popen2.* and
commands.*. To make it easier to compare subprocess with those other
modules, this week I will re-create earlier examples using the functions
being replaced.

Read more at pymotw.com: subprocess

PyMOTW: pickle and cPickle

The pickle module implements an algorithm for turning an arbitrary
Python object into a series of bytes (“serializing” the object). The
byte stream can then be transmitted or stored, and later reconstructed
to create a new object with the same characteristics.

The cPickle module implements the same algorithm, in C instead of
Python. It is many times faster than the Python implementation, but does
not allow the user to subclass from Pickle. If sub-classing is not
important for your use, you probably want to use cPickle.

Read more at pymotw.com: pickle