1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

     2 %Tutorial slides on Python.

     3 %

     4 % Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in>

     5 % Copyright (c) 2005-2009, Prabhu Ramachandran

     6 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

     7 

     8 \documentclass[14pt,compress]{beamer}

     9 %\documentclass[draft]{beamer}

    10 %\documentclass[compress,handout]{beamer}

    11 %\usepackage{pgfpages} 

    12 %\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm]

    13 

    14 % Modified from: generic-ornate-15min-45min.de.tex

    15 \mode<presentation>

    16 {

    17   \usetheme{Warsaw}

    18   \useoutertheme{split}

    19   \setbeamercovered{transparent}

    20 }

    21 

    22 \usepackage[english]{babel}

    23 \usepackage[latin1]{inputenc}

    24 %\usepackage{times}

    25 \usepackage[T1]{fontenc}

    26 

    27 % Taken from Fernando's slides.

    28 \usepackage{ae,aecompl}

    29 \usepackage{mathpazo,courier,euler}

    30 \usepackage[scaled=.95]{helvet}

    31 

    32 \definecolor{darkgreen}{rgb}{0,0.5,0}

    33 

    34 \usepackage{listings}

    35 \lstset{language=Python,

    36     basicstyle=\ttfamily\bfseries,

    37     commentstyle=\color{red}\itshape,

    38   stringstyle=\color{darkgreen},

    39   showstringspaces=false,

    40   keywordstyle=\color{blue}\bfseries}

    41 

    42 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    43 % Macros

    44 \setbeamercolor{emphbar}{bg=blue!20, fg=black}

    45 \newcommand{\emphbar}[1]

    46 {\begin{beamercolorbox}[rounded=true]{emphbar} 

    47       {#1}

    48  \end{beamercolorbox}

    49 }

    50 \newcounter{time}

    51 \setcounter{time}{0}

    52 \newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}

    53 

    54 \newcommand{\typ}[1]{\texttt{#1}}

    55 

    56 \newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}}  }

    57 

    58 %%% This is from Fernando's setup.

    59 % \usepackage{color}

    60 % \definecolor{orange}{cmyk}{0,0.4,0.8,0.2}

    61 % % Use and configure listings package for nicely formatted code

    62 % \usepackage{listings}

    63 % \lstset{

    64 %    language=Python,

    65 %    basicstyle=\small\ttfamily,

    66 %    commentstyle=\ttfamily\color{blue},

    67 %    stringstyle=\ttfamily\color{orange},

    68 %    showstringspaces=false,

    69 %    breaklines=true,

    70 %    postbreak = \space\dots

    71 % }

    72 

    73 

    74 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    75 % Title page

    76 \title[Basic Python]{Python:\\A formal approach}

    77 

    78 \author[FOSSEE Team] {The FOSSEE Group}

    79 

    80 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}

    81 \date[] {1, November 2009\\Day 2, Session 1}

    82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

    83 

    84 %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}

    85 %\logo{\pgfuseimage{iitmlogo}}

    86 

    87 

    88 %% Delete this, if you do not want the table of contents to pop up at

    89 %% the beginning of each subsection:

    90 \AtBeginSubsection[]

    91 {

    92   \begin{frame}<beamer>

    93     \frametitle{Outline}

    94     \tableofcontents[currentsection,currentsubsection]

    95   \end{frame}

    96 }

    97 

    98 \AtBeginSection[]

    99 {

   100   \begin{frame}<beamer>

   101     \frametitle{Outline}

   102     \tableofcontents[currentsection,currentsubsection]

   103   \end{frame}

   104 }

   105 

   106 % If you wish to uncover everything in a step-wise fashion, uncomment

   107 % the following command: 

   108 %\beamerdefaultoverlayspecification{<+->}

   109 

   110 %\includeonlyframes{current,current1,current2,current3,current4,current5,current6}

   111 

   112 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

   113 % DOCUMENT STARTS

   114 \begin{document}

   115 

   116 \begin{frame}

   117   \titlepage

   118 \end{frame}

   119 

   120 \begin{frame}

   121   \frametitle{Outline}

   122   \tableofcontents

   123   % You might wish to add the option [pausesections]

   124 \end{frame}

   125 

   126 \section{Data types}

   127 

   128 \begin{frame}

   129   \frametitle{Primitive Data types}

   130   \begin{itemize}

   131     \item Numbers: float, int, complex

   132     \item Strings

   133     \item Boolean

   134   \end{itemize}

   135 \end{frame}

   136 

   137 \subsection{Numbers}

   138 \begin{frame}[fragile]

   139   \frametitle{Numbers}

   140   \begin{itemize}

   141     \item \kwrd{int}\\ Any whole number is an \kwrd{int}, no matter what the size!

   142   \begin{lstlisting}

   143 In []: a = 13

   144 

   145 In []: a = 99999999999999999999

   146   \end{lstlisting}

   147     \item \kwrd{float}

   148   \begin{lstlisting}

   149 In []: fl = 3.141592

   150   \end{lstlisting}

   151   \end{itemize}

   152 \end{frame}

   153 

   154 \begin{frame}[fragile]

   155 \frametitle{Complex numbers}

   156   \begin{lstlisting}

   157 In []: cplx = 3+4j

   158 

   159 In []: abs(cplx)

   160 Out[]: 5.0

   161 

   162 In []: cplx.imag

   163 Out[]: 4.0

   164 

   165 In []: cplx.real

   166 Out[]: 3.0

   167   \end{lstlisting}

   168 \end{frame}

   169 

   170 \subsection{Boolean}

   171 \begin{frame}{Boolean}

   172   \begin{itemize}

   173     \item \kwrd{True}

   174     \item \kwrd{False}

   175     \item \kwrd{not}

   176     \item \kwrd{and}

   177     \item \kwrd{or}

   178   \end{itemize}

   179 \end{frame}

   180 

   181 \subsection{Strings}

   182 \begin{frame}[fragile]

   183   \frametitle{String methods}

   184 Strings were introduced previously, let us now look at them in a little more detail.

   185   \begin{lstlisting}

   186 In []: a = 'hello world'

   187 

   188 In []: a.startswith('hell')

   189 Out[]: True

   190 

   191 In []: a.endswith('ld')

   192 Out[]: True

   193   \end{lstlisting}

   194 \end{frame}

   195 

   196 \begin{frame}[fragile]

   197 \frametitle{Still with strings}

   198 We saw split() previously. join() is the opposite of split()

   199   \begin{lstlisting}

   200 In []: ''.join(['a', 'b', 'c'])

   201 Out[]: 'abc'

   202   \end{lstlisting}

   203   \begin{block}{Note:}

   204 Strings are immutable.\\ That is string variables cannot be changed.

   205   \end{block}

   206 \end{frame}

   207 

   208 \begin{frame}[fragile]

   209 \frametitle{String formatting}

   210   \begin{lstlisting}

   211 In []: x, y = 1, 1.234

   212 In []: 'x is %s, y is %s' %(x, y)

   213 Out[]: 'x is 1, y is 1.234'

   214   \end{lstlisting}

   215   \small

   216 \url{docs.python.org/lib/typesseq-strings.html}\\

   217 \inctime{10}

   218 \end{frame}

   219 

   220 \section{Relational and logical operators}

   221 \begin{frame}[fragile]

   222   \frametitle{Relational and logical operators}

   223   \begin{lstlisting}

   224 In []: pos, zer, neg = 1, 0, -1

   225 In []: pos == neg

   226 Out[]: False

   227 

   228 In []: pos >= neg

   229 Out[]: True

   230 

   231 In []: neg < zer < pos

   232 Out[]: True

   233 

   234 In []: pos + neg != zer

   235 Out[]: False

   236   \end{lstlisting}

   237 \inctime{5}

   238 \end{frame}

   239 

   240 \begin{frame}

   241   {A classic problem}

   242   \begin{block}

   243     {Interchange values}

   244     How to interchange values of two variables? 

   245   \end{block}

   246   \pause

   247   \begin{block}{Note:}

   248     This Python idiom works for all types of variables.\\

   249 They need not be of the same type!

   250   \end{block}

   251   \inctime{}

   252 \end{frame}

   253 

   254 \section{Control flow}

   255 \begin{frame}

   256   \frametitle{Control flow constructs}  

   257   \begin{itemize}

   258   \item \kwrd{if/elif/else}: branching

   259   \item \kwrd{while}: looping

   260   \item \kwrd{for}: iterating 

   261   \item \kwrd{break, continue}: modify loop 

   262   \item \kwrd{pass}: syntactic filler

   263   \end{itemize}

   264 \end{frame}

   265 

   266 \subsection{Basic Conditional flow}

   267 \begin{frame}[fragile]

   268   \frametitle{\typ{If...elif...else} example}

   269 \begin{lstlisting}

   270 x = int(raw_input("Enter an integer:"))

   271 if x < 0:

   272      print 'Be positive!'

   273 elif x == 0:

   274      print 'Zero'

   275 elif x == 1:

   276      print 'Single'

   277 else:

   278      print 'More'

   279 \end{lstlisting}

   280 \end{frame}

   281 

   282 \begin{frame}{Simple IO}

   283   \begin{block}

   284     {Console Input}

   285     \texttt{raw\_input()} waits for user input.\\Prompt string is optional.\\

   286     All keystrokes are Strings!\\\texttt{int()} converts string to int.

   287   \end{block}

   288   \begin{block}

   289     {Console output}

   290     \texttt{print} is straight forward. Note the distinction between \texttt{print x} and \texttt{print x,}

   291   \end{block}

   292 \end{frame}

   293 

   294 \subsection{Basic Looping}

   295 \begin{frame}[fragile]

   296   \frametitle{\kwrd{while}}

   297 Example: Fibonacci series

   298   \begin{lstlisting}

   299 # the sum of two elements

   300 # defines the next

   301 a, b = 0, 1

   302 while b < 10:

   303     print b,

   304     a, b = b, a + b 

   305 \end{lstlisting}

   306 \typ{1 1 2 3 5 8}\\  

   307 \end{frame}

   308 

   309 \begin{frame}[fragile]

   310 \frametitle{\kwrd{range()}}

   311 \kwrd{range([start,] stop[, step])}\\

   312 \begin{itemize}

   313   \item \alert {range() returns a list of integers}

   314   \item \alert {The start and the step arguments are optional}  

   315 \end{itemize}

   316 \end{frame}

   317 

   318 \begin{frame}[fragile]

   319   \frametitle{\kwrd{for}}

   320 Example: print squares of first \typ{n} numbers

   321   \begin{lstlisting}

   322 In []: for i in range(5):

   323  ....:     print i, i * i

   324  ....:     

   325  ....:     

   326 0 0

   327 1 1

   328 2 4

   329 3 9

   330 4 16

   331 \end{lstlisting}

   332 \inctime{15}

   333 \end{frame}

   334 

   335 \section{Lists}

   336 \begin{frame}[fragile]

   337 \frametitle{More List methods}

   338 \begin{lstlisting}

   339 In []: lst = [1,2,3,4,5,6,7,8]

   340 In []: lst.reverse()

   341 In []: lst

   342 Out[]: [8, 7, 6, 5, 4, 3, 2, 1]

   343 

   344 In []: lst.extend([0, -1, -2])

   345 In []: lst

   346 Out[]: [8, 7, 6, 5, 4, 3, 2, 1, 0, -1, -2]

   347 

   348 In []: lst.remove(0)

   349 In []: lst

   350 Out[]: [8, 7, 6, 5, 4, 3, 2, 1, -1, -2]

   351 \end{lstlisting}

   352 \end{frame}

   353 

   354 \begin{frame}[fragile]

   355 \frametitle{List containership}

   356 \begin{lstlisting}

   357 In []: a = 8

   358 

   359 In []: a in lst

   360 Out[]: True

   361 

   362 In []: b = 10

   363 In []: b in lst

   364 Out[]: False

   365 

   366 In []: b not in lst

   367 Out[]: True

   368 \end{lstlisting}

   369 \inctime{10}

   370 \end{frame}

   371 

   372 \section{Tuples}

   373 \begin{frame}[fragile]

   374 \frametitle{Tuples: Immutable lists}

   375 \begin{lstlisting}

   376 In []: tup = (1,2,3,4,5,6,7,8)

   377 In []: tup[0]+tup[3]+tup[-1]

   378 Out[]: 13

   379 \end{lstlisting}

   380 \begin{block}{Note:}

   381 \begin{itemize}

   382 \item Tuples are immutable - cannot be changed

   383 \item Multiple return values in a function are actually tuples

   384 \item Tuples are working behind the scenes in exchanging values - Tuple Unpacking

   385 \end{itemize}

   386 \end{block}

   387 \inctime{5}

   388 \end{frame}

   389 

   390 \section{Dictionaries}

   391 \begin{frame}[fragile]

   392 \frametitle{Dictionaries}

   393   \alert {lists and tuples: integer indexes :: dictionaries: string indexes}

   394 \begin{lstlisting}

   395 In []: player = {'Mat': 134, 'Inn': 233, 'Runs': 10823, 'Avg': 52.53}

   396 

   397 In []: player['Avg']

   398 Out[]: 52.530000000000001

   399 

   400 In []: player.keys()

   401 Out[]: ['Runs', 'Inn', 'Avg', 'Mat']

   402 

   403 In []: player.values()

   404 Out[]: [10823, 233, 52.530000000000001, 134]

   405 \end{lstlisting}

   406 \end{frame}

   407 

   408 \begin{frame}{Dictionaries}

   409 \begin{itemize}

   410 \item Duplicate keys are not allowed!

   411 \item Dictionaries are iterable through keys.

   412 \end{itemize}

   413 \inctime{5}

   414 \end{frame}

   415 

   416 \end{document}