initial commit of sets
authornishanth
Wed, 15 Sep 2010 22:09:31 +0530
changeset 142 7bc28afff7ab
parent 141 05a7b0506134
child 143 e75538bca178
initial commit of sets
sets.rst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sets.rst	Wed Sep 15 22:09:31 2010 +0530
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+Hello friends and welcome to the tutorial on Sets
+
+{{{ Show the slide containing title }}}
+
+{{{ Show the slide containing the outline slide }}}
+
+In this tutorial, we shall learn
+
+ * sets
+ * operations on sets
+
+Sets are data structures which contain unique elements. In other words,
+duplicates are not allowed in sets.
+
+Lets look at how to input sets.
+type
+::
+ 
+    a_list = [1, 2, 1, 4, 5, 6, 7]
+    a = set(a_list)
+    a
+     
+We can see that duplicates are removed and the set contains only unique
+elements. 
+::
+
+    f10 = set([1, 2, 3, 5, 8])
+    p10 = set([2, 3, 5, 7])
+
+f10 is the set of fibonacci numbers from 1 to 10.
+p10 is the set of prime numbers from 1 to 10.
+
+Sets can be iterated upon just like lists and tuples. 
+::
+
+    for i in f10:
+        print i,
+
+prints the elements of f10.
+
+The length and containership check on sets is similar as in lists and tuples.
+::
+
+    len(f10)
+
+shows 5. And
+::
+
+    2 in f10
+
+prints False
+
+The order in which elements are organised in a set is not to be relied upon 
+since sets do not support indexing. Hence, slicing and striding are not valid
+on sets.
+
+Various operations that we do on sets are possible here also.
+The | character stands for union
+::
+
+    f10 | p10
+
+gives us the union of f10 and p10
+
+The & character stands for intersection.
+::
+
+    f10 & p10
+
+gives the intersection
+
+similarly,
+::
+
+    f10 - p10
+
+gives all the elements that are in f10 but not in p10
+
+::
+
+    f10 ^ p10
+
+is all the elements in f10 union p10 but not in f10 intersection p10. In
+mathematical terms, it gives the symmectric difference.
+
+{{{ Pause here and try out the following exercises }}}
+
+%% 1 %% Given a list of marks, marks = [20, 23, 22, 23, 20, 21, 23] 
+        list all the duplicates
+
+{{{ continue from paused state }}}
+
+Duplicates marks are the marks left out when we remove each element of the 
+list exactly one time.
+
+::
+
+    marks = [20, 23, 22, 23, 20, 21, 23] 
+    marks_set = set(marks)
+    for mark in marks_set:
+        marks.remove(mark)
+
+    # we are now left with only duplicates in the list marks
+    duplicates = set(marks)
+
+{{{ Show summary slide }}}
+
+This brings us to the end of the tutorial.
+we have learnt
+
+ * How to make sets from lists
+ * How to input sets
+ * The various similarities with lists like length and containership
+ * How to perform union, intersection and symmectric difference operations
+
+{{{ Show the "sponsored by FOSSEE" slide }}}
+
+#[Nishanth]: Will add this line after all of us fix on one.
+This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
+
+Hope you have enjoyed and found it useful.
+Thankyou
+ 
+.. Author              : Nishanth
+   Internal Reviewer 1 : 
+   Internal Reviewer 2 : 
+   External Reviewer   :