# sets are unordered collections of unique hashable elements

# Python23 tested vegaseat 09mar2005

# Python v2.4 has sets built in

import sets

print "List the functions within module 'sets':"

for funk in dir(sets):

print funk

# create an empty set

set1 = set([])

# now load the set

for k in range(10):

set1.add(k)

print "nLoaded a set with 0 to 9:"

print set1

set1.add(7)

print "Tried to add another 7, but it was already there:"

print set1

# make a list of fruits as you put them into a basket

basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']

print "nThe original list of fruits:"

print basket

# create a set from the list, removes the duplicates

fruits = sets.Set(basket)

print "nThe set is unique, but the order has changed:"

print fruits

# let's get rid of some duplicate words

str1 = "Senator Strom Thurmond dressed as as Tarzan"

print "nOriginal string:"

print str1

print "A list of the words in the string:"

wrdList1 = str1.split()

print wrdList1

# now create a set of unique words

strSet = sets.Set(wrdList1)

print "The set of the words in the string:"

print strSet

print "Convert set back to string (order has changed!):"

print " ".join(strSet)

print

# comparing two sets, bear with me ...

colorSet1 = sets.Set(['red','green','blue','black','orange','white'])

colorSet2 = sets.Set(['black','maroon','grey','blue'])

print "colorSet1 =", colorSet1

print "colorSet2 =", colorSet2

# same as (colorSet1 - colorSet2)

colorSet3 = colorSet1.difference(colorSet2)

print "nThese are the colors in colorSet1 that are not in colorSet2:"

print colorSet3

# same as (colorSet1 | colorSet2)

colorSet4 = colorSet1.union(colorSet2)

print "nThese are the colors appearing in both sets:"

print colorSet4

# same as (colorSet1 ^ colorSet2)

colorSet5 = colorSet1.symmetric_difference(colorSet2)

print "nThese are the colors in colorSet1 or in colorSet2, but not both:"

print colorSet5

# same as (colorSet1 & colorSet2)

colorSet6 = colorSet1.intersection(colorSet2)

print "nThese are the colors common to colorSet1 and colorSet2:"

print colorSet6