Useful Python modules

Getting the current time and date

The time module offers functions for getting the current time and date.

import time
s = time.asctime() # as string
i = time.time() # as float

Accessing web pages

The HTML code of web pages and downloadable files from the web can be accessed in a similar way as reading files:

import urllib
url = 'http://www.google.com'
page = urllib.urlopen(url)
print page.read()

Finding out what is in a module

The contents of any module can be examined with:

print dir( name_of_module )
help( name_of_module )

Creating plots

The Matplotlib library contains a wide range of possibilities for creating graphs. See the 'gallery' link on http://matplotlib.sourceforge.net for examples. It needs to be installed separately.

from pylab import *

Database access

Numpy is a library that allows operating on arrays and matrices. It needs to be installed separately. See: http://numpy.scipy.org

import numpy
a = numpy.array( [1,2,3,4,5,6] )
print a+10, a*a

Image manipulation

The Python Imaging Library PIL is a powerful tool for working with images (changing formats, resizing, cutting, drawing). It needs to be installed separately. See http://www.pythonware.com/products/pil .