Simple python examples

What you want What it is called Examples
Outputprintprinting1.py
randomwalk4.py
Loopsforloop1.py
dowhile.py
Command-line inputsys.argv commandline1.py
commandline2.py
randomwalk4.py
Function definitiondef fact.py
randomwalk4.py
randomwalk5.py
Reading in lines from standard inputsys.stdin reading1.py
Substitution using regular expressionsre reading1.py
length of a listlencommandline2.py
Convert string to integerintcommandline2.py
find something in listfind1.py
Sort a listsortsort1.py
Split a stringsplit1.py
Reading lines from a fileopen, readlinesreading2.py
Random numbersrandom.random()randomwalk4.py
randomwalk5.py
Automatic execution__name__, __main__randomwalk4.py
randomwalk5.py
Plotting graphsGnuplot randomwalk5.py
Plotting histogramspylab.hist histo1.py
Automated testingdoctest
(explanation)
DocExample.py
DocExample2.py
AlanDice.py
AlanDice2.py
decomposeSquares.py
Recursion decomposeSquares.py

find1.py

#
# python/examples/find1.py
#
# How to find the first item in a
# list for which a function is true

def find(f, seq):
    """
    Return first item in sequence where f(item) == True.

    Example 1:
    >>> find( IsPrime , [ 4, 9, 13, 17 ] )
    13
    
    Example 2, using a function defined on the fly with 'lambda':
      to find in the list 'codewords' the first element
      whose attribute 'index' is equal to s,
    >>> co = find(lambda p: p.index == s, codewords)
    """
    for item in seq:
        if f(item): 
            return item

def IsPrime( n ) :
    """
    >>> IsPrime( 5 )
    True
    >>> IsPrime( 10 )
    False
    """
    for i in range(2,n) :
        if (n%i == 0):
            return False
    return True        

# Example by David MacKay www.aims.ac.za/~mackay/
# Solution from
#  http://naeblis.cx/rtomayko/2004/09/13/
# cleanest-python-find-in-list-function

David MacKay / python resources /

David MacKay / Computational Physics wiki (UCAM only) / C++ resources /