--- a/day1/session3.tex	Wed Oct 28 16:05:14 2009 +0530
+++ b/day1/session3.tex	Wed Oct 28 16:05:38 2009 +0530
@@ -126,6 +126,7 @@
 %%   % You might wish to add the option [pausesections]
 %% \end{frame}
 
+\section{Statistics}
 \begin{frame}
   \frametitle{More on data processing}
   \begin{block}{}
@@ -178,8 +179,10 @@
     \item Pass/Fail (P/F)
     \item Withdrawn (W)
   \end{itemize}
+  \inctime{5}
 \end{frame}
 
+\subsection{Data processing}
 \begin{frame}[fragile]
   \frametitle{File reading and parsing \ldots}
   \begin{lstlisting}
@@ -188,22 +191,23 @@
   \end{lstlisting}
 \end{frame}
 
+\subsection{Dictionary}
 \begin{frame}[fragile]
   \frametitle{Dictionary: Introduction}
   \begin{itemize}
     \item lists index: 0 \ldots n
     \item dictionaries index using strings
   \end{itemize}
-\begin{block}{Example}
+  \begin{block}{Example}
 d = \{ ``Hitchhiker's guide'' : 42,
      ``Terminator'' : ``I'll be back''\}\\
 d[``Terminator''] => ``I'll be back''
-\end{block}
+  \end{block}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{Dictionary: Introduction}
-\begin{lstlisting}
+  \begin{lstlisting}
 In [1]: d = {"Hitchhiker's guide" : 42,
       "Terminator" : "I'll be back"}
 
@@ -215,24 +219,24 @@
 
 In [4]: "Guido" in d
 Out[4]: False
-\end{lstlisting}
+  \end{lstlisting}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{Dictionary: Introduction}
-\begin{lstlisting}
+  \begin{lstlisting}
 In [5]: d.keys()
 Out[5]: ['Terminator', "Hitchhiker's 
                               guide"]
 
 In [6]: d.values()
 Out[6]: ["I'll be back", 42]
-\end{lstlisting}
+  \end{lstlisting}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{enumerate: Iterating through list indices}
-\begin{lstlisting}
+  \begin{lstlisting}
 In [1]: names = ["Guido","Alex", "Tim"]
 
 In [2]: for i, name in enumerate(names):
@@ -241,15 +245,16 @@
 0 Guido
 1 Alex
 2 Tim
-\end{lstlisting}
+  \end{lstlisting}
+  \inctime{5}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{Dictionary: Building parsed data}
-    Let our dictionary be:
-    \begin{lstlisting}
+  Let our dictionary be:
+  \begin{lstlisting}
 science = {} # is an empty dictionary
-    \end{lstlisting}
+  \end{lstlisting}
 \end{frame}
 
 \begin{frame}[fragile]
@@ -291,6 +296,7 @@
   \end{lstlisting}
 \end{frame}
 
+\subsection{Visualizing the data}
 \begin{frame}[fragile]
   \frametitle{Pie charts}
   \small
@@ -308,6 +314,7 @@
 \includegraphics[height=2in, interpolate=true]{data/science}
     \column{0.8\textwidth}
 \end{columns}
+  \inctime{5}
 \end{frame}
 
 \begin{frame}[fragile]
@@ -381,6 +388,7 @@
   \includegraphics[height=3in, interpolate=true]{data/all_regions}
 \end{frame}
 
+\subsection{Obtaining stastics}
 \begin{frame}[fragile]
   \frametitle{Obtaining statistics}
   \begin{lstlisting}
@@ -395,6 +403,7 @@
 print "Standard Deviation: ",
               std(math_scores)
   \end{lstlisting}
+  \inctime{15}
 \end{frame}
 
 \begin{frame}[fragile]

--- a/day1/session4.tex	Wed Oct 28 16:05:14 2009 +0530
+++ b/day1/session4.tex	Wed Oct 28 16:05:38 2009 +0530
@@ -136,14 +136,16 @@
 \begin{frame}[fragile]
 \frametitle{Matrices: Initializing}
 \begin{lstlisting}
-In []: A = ([[5, 2, 4], 
-            [-3, 6, 2], 
-            [3, -3, 1]])
-
+In []: A = matrix([[ 1,  1,  2, -1],
+                   [ 2,  5, -1, -9],
+                   [ 2,  1, -1,  3],
+                   [ 1, -3,  2,  7]])
 In []: A
-Out[]: [[5, 2, 4], 
-        [-3, 6, 2], 
-        [3, -3, 1]]
+Out[]: 
+matrix([[ 1,  1,  2, -1],
+        [ 2,  5, -1, -9],
+        [ 2,  1, -1,  3],
+        [ 1, -3,  2,  7]])
 \end{lstlisting}
 \end{frame}
 
@@ -153,10 +155,11 @@
 \frametitle{Transpose of a Matrix}
 \begin{lstlisting}
 In []: linalg.transpose(A)
-Out[]: 
-matrix([[ 5, -3,  3],
-        [ 2,  6, -3],
-        [ 4,  2,  1]])
+Out[]:
+matrix([[ 1,  2,  2,  1],
+        [ 1,  5,  1, -3],
+        [ 2, -1, -1,  2],
+        [-1, -9,  3,  7]])
 \end{lstlisting}
 \end{frame}
 
@@ -164,22 +167,23 @@
   \frametitle{Sum of all elements}
   \begin{lstlisting}
 In []: linalg.sum(A)
-Out[]: 17
+Out[]: 12
   \end{lstlisting}
 \end{frame}
 
 \begin{frame}[fragile]
   \frametitle{Matrix Addition}
   \begin{lstlisting}
-In []: B = matrix([[3,2,-1],
-                   [2,-2,4],
-                   [-1, 0.5, -1]])
-
-In []: linalg.add(A, B)
+In []: B = matrix([[3,2,-1,5],
+                   [2,-2,4,9],
+                   [-1,0.5,-1,-7],
+                   [9,-5,7,3]])
+In []: linalg.add(A,B)
 Out[]: 
-matrix([[ 8. ,  4. ,  3. ],
-        [-1. ,  4. ,  6. ],
-        [ 2. , -2.5,  0. ]])
+matrix([[  4. ,   3. ,   1. ,   4. ],
+        [  4. ,   3. ,   3. ,   0. ],
+        [  1. ,   1.5,  -2. ,  -4. ],
+        [ 10. ,  -8. ,   9. ,  10. ]])
   \end{lstlisting}
 \end{frame}
 
@@ -188,9 +192,10 @@
 \begin{lstlisting}
 In []: linalg.multiply(A, B)
 Out[]: 
-matrix([[ 15. ,   4. ,  -4. ],
-        [ -6. , -12. ,   8. ],
-        [ -3. ,  -1.5,  -1. ]])
+matrix([[  3. ,   2. ,  -2. ,  -5. ],
+        [  4. , -10. ,  -4. , -81. ],
+        [ -2. ,   0.5,   1. , -21. ],
+        [  9. ,  15. ,  14. ,  21. ]])
 \end{lstlisting}
 \end{frame}
 
@@ -200,9 +205,10 @@
 \begin{lstlisting}
 In []: linalg.inv(A)
 Out[]: 
-array([[ 0.28571429, -0.33333333, -0.47619048],
-       [ 0.21428571, -0.16666667, -0.52380952],
-       [-0.21428571,  0.5       ,  0.85714286]])
+matrix([[-0.5 ,  0.55, -0.15,  0.7 ],
+        [ 0.75, -0.5 ,  0.5 , -0.75],
+        [ 0.5 , -0.15, -0.05, -0.1 ],
+        [ 0.25, -0.25,  0.25, -0.25]])
 \end{lstlisting}
 \end{small}
 \end{frame}
@@ -211,7 +217,7 @@
 \frametitle{Determinant}
 \begin{lstlisting}
 In []: det(A)
-Out[]: 42.0
+Out[66]: 80.0
 \end{lstlisting}
 \end{frame}
 
@@ -221,10 +227,11 @@
 \begin{lstlisting}
 In []: linalg.eig(A)
 Out[]: 
-(array([ 7.,  2.,  3.]),
- matrix([[-0.57735027,  0.42640143,  0.37139068],
-        [ 0.57735027,  0.63960215,  0.74278135],
-        [-0.57735027, -0.63960215, -0.55708601]]))
+(array([ 11.41026155,   3.71581643,  -0.81723144,  -2.30884654]),
+ matrix([[ 0.12300187, -0.53899627,  0.63269982,  0.56024583],
+        [ 0.8225266 , -0.67562403, -0.63919634, -0.20747251],
+        [-0.04763219, -0.47575453, -0.3709497 , -0.80066041],
+        [-0.55321941, -0.16331814, -0.23133374,  0.04497415]]))
 \end{lstlisting}
 \end{small}
 \end{frame}
@@ -232,8 +239,8 @@
 \begin{frame}[fragile]
 \frametitle{Computing Norms}
 \begin{lstlisting}
-  In []: linalg.norm(A)
-  Out[]: 10.63014581273465
+In []: linalg.norm(A)
+Out[]: 14.0
 \end{lstlisting}
 \end{frame}
 
@@ -243,14 +250,16 @@
   \begin{lstlisting}
 In []: linalg.svd(A)
 Out[]: 
-(matrix([[-0.13391246, -0.94558684, -0.29653495],
-        [ 0.84641267, -0.26476432,  0.46204486],
-        [-0.51541542, -0.18911737,  0.83581192]]),
- array([ 7.96445022,  7.        ,  0.75334767]),
- matrix([[-0.59703387,  0.79815896,  0.08057807],
-        [-0.64299905, -0.41605821, -0.64299905],
-        [-0.47969029, -0.43570384,  0.7616163 ]]))
-  \end{lstlisting}
+(matrix([[-0.08588113,  0.29164297, -0.74892678,  0.58879325],
+        [-0.79093255,  0.39530483, -0.11188116, -0.45347812],
+        [ 0.1523891 ,  0.78799358,  0.51966138,  0.29290907],
+        [ 0.58636823,  0.37113957, -0.39565558, -0.60156827]]),
+ array([ 13.17656506,   3.76954116,   2.79959047,   0.57531379]),
+ matrix([[-0.05893795, -0.42858358,  0.12442679,  0.89295039],
+        [ 0.80364672,  0.51537891,  0.03774111,  0.29514767],
+        [-0.11752501,  0.14226922, -0.96333552,  0.19476145],
+        [-0.58040171,  0.72832696,  0.23468759,  0.27855956]]))
+\end{lstlisting}
   \end{small}
 \end{frame}
 
@@ -282,8 +291,6 @@
     In []: b = matrix([[1], [-2], [0]])
     In []: x = linalg.solve(A, b)
     In []: Ax = dot(A, x)
-    In []: allclose(Ax, b)
-    Out[]: True
   \end{lstlisting}
 \end{frame}
 
@@ -295,13 +302,44 @@
 array([[ 1.],
        [-2.],
        [-2.]])
+\end{lstlisting}
+\end{frame}
 
+\begin{frame}[fragile]
+\frametitle{Let's check!}
+\begin{lstlisting}
 In []: Ax
 Out[]: 
 matrix([[  1.00000000e+00],
         [ -2.00000000e+00],
         [  2.22044605e-16]])
 \end{lstlisting}
+\begin{block}{}
+The last term in the matrix is actually \alert{0}!\\
+We can use \kwrd{allclose()} to check.
+\end{block}
+\begin{lstlisting}
+In []: allclose(Ax, b)
+Out[]: True
+\end{lstlisting}
+\end{frame}
+
+\subsection{Exercises}
+
+\begin{frame}[fragile]
+\frametitle{Problem}
+
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Problem}
+Solve the set of equations:
+\begin{align*}
+  x + y + 2z -w & = 3\\
+  2x + 5y - z - 9w & = -3\\
+  2x + y -z + 3w & = -11 \\
+  x - 3y + 2z + 7w & = -5\\
+\end{align*}
 \end{frame}
 
 \section{Summary}

--- a/day2/session1.tex	Wed Oct 28 16:05:14 2009 +0530
+++ b/day2/session1.tex	Wed Oct 28 16:05:38 2009 +0530
@@ -182,6 +182,7 @@
 In [4]: f and t
 Out[4]: False
   \end{lstlisting}
+  \inctime{5}
 \end{frame}
 
 \subsection{Strings}
@@ -252,10 +253,8 @@
 In [2]: 'x is %s, y is %s' %(x, y)
 Out[2]: 'x is 1, y is 1.234'
   \end{lstlisting}
-\emphbar{
-\url{http://docs.python.org/library/stdtypes.html}\\
-}
-\inctime{10}
+  \emphbar{\url{http://docs.python.org/library/stdtypes.html}}
+  \inctime{10}
 \end{frame}
 
 \section{Operators}
@@ -338,7 +337,6 @@
 In [5]: pos + neg != zer
 Out[5]: False
   \end{lstlisting}
-\inctime{5}
 \end{frame}
 
 \begin{frame}[fragile]
@@ -378,19 +376,6 @@
   \inctime{15}
 \end{frame}
 
-\begin{frame}[fragile] \frametitle{A question of good style}
-  \begin{lstlisting}
-    amount = 12.68
-    denom = 0.05
-    nCoins = round(amount/denom)
-    rAmount = nCoins * denom
-  \end{lstlisting}
-  \pause
-  \begin{block}{Style Rule \#1}
-    Naming is 80\% of programming
-  \end{block}
-\end{frame}
-
 \section{Simple IO}
 \begin{frame}{Simple IO}
   \begin{block}
@@ -419,7 +404,7 @@
 \subsection{Basic Conditional flow}
 \begin{frame}[fragile]
   \frametitle{\typ{If...elif...else} example}
-\begin{lstlisting}
+  \begin{lstlisting}
 x = int(raw_input("Enter an integer:"))
 if x < 0:
      print 'Be positive!'
@@ -429,7 +414,8 @@
      print 'Single'
 else:
      print 'More'
-\end{lstlisting}
+  \end{lstlisting}
+  \inctime{10}
 \end{frame}
 
 \subsection{Basic Looping}
@@ -470,7 +456,7 @@
 3 9
 4 16
 \end{lstlisting}
-\inctime{15}
+\inctime{5}
 \end{frame}
 
 \subsection{Exercises}
@@ -496,10 +482,9 @@
   \item It appears that for all starting values there is a cycle of 4, 2, 1 at which the procedure loops.
 \end{enumerate}
     Write a program that accepts the starting value and prints out the Collatz sequence.
-
 \end{frame}
 
-\begin{frame}[fragile]{Problem 1.4}
+\begin{frame}[fragile]{Problem 1.3}
   Write a program that prints the following pyramid on the screen. 
   \begin{lstlisting}
 1
@@ -510,7 +495,17 @@
 The number of lines must be obtained from the user as input.\\
 \pause
 \emphbar{When can your code fail?}
-\only<2->{\inctime{20}}
+\only<2->{\inctime{10}}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{What did we learn?}
+  \begin{itemize}
+    \item Basic data types
+    \item Arithematic, logical and relational operations
+    \item Conditional structures
+    \item Loops
+  \end{itemize}
 \end{frame}
 
 \end{document}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/day2/session2.tex	Wed Oct 28 16:05:38 2009 +0530
@@ -0,0 +1,522 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%Tutorial slides on Python.
+%
+% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>
+% Copyright (c) 2005-2009, Prabhu Ramachandran
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\documentclass[14pt,compress]{beamer}
+%\documentclass[draft]{beamer}
+%\documentclass[compress,handout]{beamer}
+%\usepackage{pgfpages} 
+%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]
+
+% Modified from: generic-ornate-15min-45min.de.tex
+\mode<presentation>
+{
+  \usetheme{Warsaw}
+  \useoutertheme{split}
+  \setbeamercovered{transparent}
+}
+
+\usepackage[english]{babel}
+\usepackage[latin1]{inputenc}
+%\usepackage{times}
+\usepackage[T1]{fontenc}
+
+% Taken from Fernando's slides.
+\usepackage{ae,aecompl}
+\usepackage{mathpazo,courier,euler}
+\usepackage[scaled=.95]{helvet}
+
+\definecolor{darkgreen}{rgb}{0,0.5,0}
+
+\usepackage{listings}
+\lstset{language=Python,
+    basicstyle=\ttfamily\bfseries,
+    commentstyle=\color{red}\itshape,
+  stringstyle=\color{darkgreen},
+  showstringspaces=false,
+  keywordstyle=\color{blue}\bfseries}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Macros
+\setbeamercolor{emphbar}{bg=blue!20, fg=black}
+\newcommand{\emphbar}[1]
+{\begin{beamercolorbox}[rounded=true]{emphbar} 
+      {#1}
+ \end{beamercolorbox}
+}
+\newcounter{time}
+\setcounter{time}{0}
+\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}
+
+\newcommand{\typ}[1]{\texttt{#1}}
+
+\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}}  }
+
+%%% This is from Fernando's setup.
+% \usepackage{color}
+% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2}
+% % Use and configure listings package for nicely formatted code
+% \usepackage{listings}
+% \lstset{
+%    language=Python,
+%    basicstyle=\small\ttfamily,
+%    commentstyle=\ttfamily\color{blue},
+%    stringstyle=\ttfamily\color{orange},
+%    showstringspaces=false,
+%    breaklines=true,
+%    postbreak = \space\dots
+% }
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Title page
+\title[Basic Python]{Python:\\A formal approach}
+
+\author[FOSSEE Team] {The FOSSEE Group}
+
+\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
+\date[] {1, November 2009\\Day 2, Session 2}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
+%\logo{\pgfuseimage{iitmlogo}}
+
+
+%% Delete this, if you do not want the table of contents to pop up at
+%% the beginning of each subsection:
+\AtBeginSubsection[]
+{
+  \begin{frame}<beamer>
+    \frametitle{Outline}
+    \tableofcontents[currentsection,currentsubsection]
+  \end{frame}
+}
+
+\AtBeginSection[]
+{
+  \begin{frame}<beamer>
+    \frametitle{Outline}
+    \tableofcontents[currentsection,currentsubsection]
+  \end{frame}
+}
+
+% If you wish to uncover everything in a step-wise fashion, uncomment
+% the following command: 
+%\beamerdefaultoverlayspecification{<+->}
+
+%\includeonlyframes{current,current1,current2,current3,current4,current5,current6}
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% DOCUMENT STARTS
+\begin{document}
+
+\begin{frame}
+  \titlepage
+\end{frame}
+
+\begin{frame}
+  \frametitle{Outline}
+  \tableofcontents
+  % You might wish to add the option [pausesections]
+\end{frame}
+
+\section{Data structures}
+\subsection{Lists}
+\begin{frame}[fragile]
+  \frametitle{Lists}
+\begin{block}{We already know that}
+  \begin{lstlisting}
+num = [1, 2, 3, 4, 5, 6, 7, 8]
+  \end{lstlisting}
+\centerline{is a list}
+\end{block}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Lists: methods}
+  \begin{lstlisting}
+In []: num.reverse()
+In []: num
+Out[]: [8, 7, 6, 5, 4, 3, 2, 1]
+
+In []: num.extend([0, -1, -2])
+In []: num
+Out[]: [8, 7, 6, 5, 4, 3, 2, 1, 0, -1]
+
+In []: num.remove(0)
+In []: num
+Out[]: [8, 7, 6, 5, 4, 3, 2, 1, -1]
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{List containership}
+\begin{lstlisting}
+In []: a = 8
+
+In []: a in num
+Out[]: True
+
+In []: b = 10
+In []: b in num
+Out[]: False
+
+In []: b not in num
+Out[]: True
+\end{lstlisting}
+\end{frame}
+
+\subsection{Tuples}
+\begin{frame}[fragile]
+\frametitle{Tuples: Immutable lists}
+\begin{lstlisting}
+In []: t = (1, 2, 3, 4, 5, 6, 7, 8)
+In []: t[0] + t[3] + t[-1]
+Out[]: 13
+\end{lstlisting}
+\begin{block}{Note:}
+\begin{itemize}
+  \item Tuples are immutable - cannot be changed
+\end{itemize}
+\end{block}
+  \inctime{10}
+\end{frame}
+
+\begin{frame}
+  {A classic problem}
+  \begin{block}
+    {Interchange values}
+    How to interchange values of two variables? 
+  \end{block}
+  \pause
+  \begin{block}{Note:}
+    This Python idiom works for all types of variables.\\
+They need not be of the same type!
+  \end{block}
+\end{frame}
+
+\subsection{Dictionaries}
+\begin{frame}[fragile]
+  \frametitle{Dictionaries: Recall}
+  \begin{lstlisting}
+In []: player = {'Mat': 134,'Inn': 233,
+          'Runs': 10823, 'Avg': 52.53}
+
+In []: player['Avg']
+Out[]: 52.530000000000001
+  \end{lstlisting}
+  \begin{block}{Note!}
+    Duplicate keys are not allowed!\\
+    Dictionaries are iterable through keys.
+  \end{block}
+\end{frame}
+
+\begin{frame} {Problem Set 2.1: Problem 2.1.1}
+You are given date strings of the form ``29, Jul 2009'', or ``4 January 2008''. In other words a number a string and another number, with a comma sometimes separating the items.Write a function that takes such a string and returns a tuple (yyyy, mm, dd) where all three elements are ints.
+\end{frame}
+
+\subsection{Set}
+\begin{frame}[fragile]
+  \frametitle{Set}
+    \begin{itemize}
+      \item Simplest container, mutable
+      \item No ordering, no duplicates
+      \item usual suspects: union, intersection, subset \ldots
+      \item >, >=, <, <=, in, \ldots
+    \end{itemize}
+    \begin{lstlisting}
+>>> f10 = set([1,2,3,5,8])
+>>> p10 = set([2,3,5,7])
+>>> f10|p10
+set([1, 2, 3, 5, 7, 8])
+>>> f10&p10
+set([2, 3, 5])
+>>> f10-p10
+set([8, 1])
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Set}
+    \begin{lstlisting}
+>>> p10-f10, f10^p10
+set([7]), set([1, 7, 8])
+>>> set([2,3]) < p10
+True
+>>> set([2,3]) <= p10
+True
+>>> 2 in p10
+True
+>>> 4 in p10
+False
+>>> len(f10)
+5
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}
+  \frametitle{Problem set 2.2}
+  \begin{description}
+    \item[2.2.1] Given a dictionary of the names of students and their marks, identify how many duplicate marks are there? and what are these?
+    \item[2.2.2] Given a string of the form ``4-7, 9, 12, 15'' find the numbers missing in this list for a given range.
+\end{description}
+\inctime{15}
+\end{frame}
+
+\section{Functions}
+\begin{frame}[fragile]
+  \frametitle{Functions}
+  \begin{itemize}
+    \item \kwrd{def} - keyword to define a function
+    \item Arguments are local to a function
+    \item Docstrings are important!
+    \item Functions can return multiple values
+  \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Functions: example}
+  \begin{lstlisting}
+def signum( r ):
+    """returns 0 if r is zero
+    -1 if r is negative
+    +1 if r is positive"""
+    if r < 0:
+        return -1
+    elif r > 0:
+        return 1
+    else:
+        return 0
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  {What does this function do?}
+\begin{lstlisting}
+def what( n ):
+    i = 1
+    while i * i < n:
+        i += 1
+    return i * i == n, i
+  \end{lstlisting}
+\end{frame}
+
+\subsection{Default arguments}
+\begin{frame}[fragile]
+  \frametitle{Functions: default arguments}
+  \small
+  \begin{lstlisting}
+def ask_ok(prompt, complaint='Yes or no!'):
+    while True:
+        ok = raw_input(prompt)
+        if ok in ('y', 'ye', 'yes'): 
+            return True
+        if ok in ('n', 'no', 'nop',
+                  'nope'): 
+            return False
+        print complaint
+
+ask_ok('?')
+ask_ok('?', '[Y/N]')
+  \end{lstlisting}
+\end{frame}
+
+\subsection{Built-in functions}
+\begin{frame}
+  {Before writing a function}
+  \begin{itemize}
+      \item Variety of builtin functions are available
+      \item \typ{abs, any, all, len, max, min}
+      \item \typ{pow, range, sum, type}
+      \item Refer here:
+          \url{http://docs.python.org/library/functions.html}
+  \end{itemize}
+  \inctime{10} 
+\end{frame}
+
+\subsection{Exercises}
+\begin{frame}{Problem set 3: Problem 3.1}
+  Write a function to return the gcd of two numbers.
+\end{frame}
+
+\begin{frame}{Problem 3.2}
+Write a program to print all primitive pythagorean triads (a, b, c) where a, b are in the range 1---100 \\
+A pythagorean triad $(a,b,c)$ has the property $a^2 + b^2 = c^2$.\\By primitive we mean triads that do not `depend' on others. For example, (4,3,5) is a variant of (3,4,5) and hence is not primitive. And (10,24,26) is easily derived from (5,12,13) and is also not primitive.
+\end{frame}
+
+\begin{frame}{Problem 3.3}
+  Write a program that generates a list of all four digit numbers that have all their digits even and are perfect squares.\newline\\\emph{For example, the output should include 6400 but not 8100 (one digit is odd) or 4248 (not a perfect square).}
+\inctime{15}
+\end{frame}
+
+\section{Modules}
+\begin{frame}[fragile]
+    {Modules}
+\begin{lstlisting}
+>>> sqrt(2)
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+NameError: name 'sqrt' is not defined
+>>> import math        
+>>> math.sqrt(2)
+1.4142135623730951
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+    {Modules}
+  \begin{itemize}
+    \item The \kwrd{import} keyword ``loads'' a module
+    \item One can also use:
+      \begin{lstlisting}
+>>> from math import sqrt
+>>> from math import *
+      \end{lstlisting}    
+    \item What is the difference?
+    \item \alert{Use the latter only in interactive mode}
+    \end{itemize}
+  \emphbar{Package hierarchies}
+      \begin{lstlisting}
+>>> from os.path import exists
+      \end{lstlisting}
+\end{frame}
+
+\begin{frame}
+  \frametitle{Modules: Standard library}
+  \begin{itemize}
+  \item Very powerful, ``Batteries included''
+  \item Some standard modules:
+    \begin{itemize}
+    \item Math: \typ{math}, \typ{random}
+    \item Internet access: \typ{urllib2}, \typ{smtplib}
+    \item System, Command line arguments: \typ{sys}
+    \item Operating system interface: \typ{os}
+    \item Regular expressions: \typ{re}
+    \item Compression: \typ{gzip}, \typ{zipfile}, and \typ{tarfile}
+    \item And a whole lot more!
+    \end{itemize}
+  \item Check out the Python Library reference:
+    \url{http://docs.python.org/library/}
+  \end{itemize}
+\inctime{5}
+\end{frame}
+
+\section{Coding Style}
+\begin{frame}{Readability and Consistency}
+    \begin{itemize}
+        \item Readability Counts!\\Code is read more often than its written.
+        \item Consistency!
+        \item Know when to be inconsistent.
+      \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile] \frametitle{A question of good style}
+  \begin{lstlisting}
+    amount = 12.68
+    denom = 0.05
+    nCoins = round(amount/denom)
+    rAmount = nCoins * denom
+  \end{lstlisting}
+  \pause
+  \begin{block}{Style Rule \#1}
+    Naming is 80\% of programming
+  \end{block}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Code Layout}
+  \begin{itemize}
+        \item Indentation
+        \item Tabs or Spaces??
+        \item Maximum Line Length
+        \item Blank Lines
+        \item Encodings
+   \end{itemize}
+\end{frame}
+
+\begin{frame}{Whitespaces in Expressions}
+  \begin{itemize}
+        \item When to use extraneous whitespaces??
+        \item When to avoid extra whitespaces??
+        \item Use one statement per line
+   \end{itemize}
+\end{frame}
+
+\begin{frame}{Comments}
+  \begin{itemize}
+        \item No comments better than contradicting comments
+        \item Block comments
+        \item Inline comments
+   \end{itemize}
+\end{frame}
+
+\begin{frame}{Docstrings}
+  \begin{itemize}
+        \item When to write docstrings?
+        \item Ending the docstrings
+        \item One liner docstrings
+   \end{itemize}
+More information at PEP8: http://www.python.org/dev/peps/pep-0008/
+\inctime{5}
+\end{frame}
+
+\section{Objects}
+\begin{frame}{Objects in general}
+    \begin{itemize}
+        \item What is an Object? (Types and classes)
+        \item identity
+        \item type
+        \item method
+      \end{itemize}
+\end{frame}
+
+\begin{frame}{Almost everything is an Object!}
+  \begin{itemize}
+    \item \typ{list}
+    \item \typ{tuple}
+    \item \typ{string}
+    \item \typ{dictionary}
+    \item \typ{function}
+    \item Of course, user defined class objects!
+  \end{itemize}
+\end {frame}
+
+\begin{frame}{Using Objects}
+  \begin{itemize}
+    \item Creating Objects: Initialization
+    \item Object Manipulation: Object methods and ``.'' operator
+  \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Objects provide consistency}
+  \small
+  \begin{lstlisting}
+for element in (1, 2, 3):
+    print element
+for key in {'one':1, 'two':2}:
+    print key
+for char in "123":
+    print char
+for line in open("myfile.txt"):
+    print line
+for line in urllib2.urlopen('http://site.com'):
+    print line
+  \end{lstlisting}
+\inctime{10}
+\end{frame}
+
+\begin{frame}
+  \frametitle{What did we learn?}
+  \begin{itemize}
+    \item Lists, Tuples, Dictionaries, Sets: creation and manipulation
+    \item More about functions
+    \item Coding style
+    \item Objects: creation and manipulation
+  \end{itemize}
+\end{frame}
+
+\end{document}