1 % Created 2010-10-11 Mon 23:02

     2 \documentclass[presentation]{beamer}

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     7 \usepackage{longtable}

     8 \usepackage{float}

     9 \usepackage{wrapfig}

    10 \usepackage{soul}

    11 \usepackage{t1enc}

    12 \usepackage{textcomp}

    13 \usepackage{marvosym}

    14 \usepackage{wasysym}

    15 \usepackage{latexsym}

    16 \usepackage{amssymb}

    17 \usepackage{hyperref}

    18 \tolerance=1000

    19 \usepackage[english]{babel} \usepackage{ae,aecompl}

    20 \usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet}

    21 \usepackage{listings}

    22 \lstset{language=Python, basicstyle=\ttfamily\bfseries,

    23 commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},

    24 showstringspaces=false, keywordstyle=\color{blue}\bfseries}

    25 \providecommand{\alert}[1]{\textbf{#1}}

    26 

    27 \title{Dictionaries}

    28 \author{FOSSEE}

    29 \date{}

    30 

    31 \usetheme{Warsaw}\usecolortheme{default}\useoutertheme{infolines}\setbeamercovered{transparent}

    32 \begin{document}

    33 

    34 \maketitle

    35 

    36 

    37 

    38 

    39 

    40 

    41 

    42 

    43 

    44 \begin{frame}

    45 \frametitle{Outline}

    46 \label{sec-1}

    47 

    48 \begin{itemize}

    49 \item Creating dictionaries

    50 

    51 \begin{itemize}

    52 \item empty dictionaries

    53 \item with data

    54 \end{itemize}

    55 

    56 \item Keys and values

    57 \item Checking for elements

    58 \item Iterating over elements

    59 \end{itemize}

    60 \end{frame}

    61 \begin{frame}

    62 \frametitle{Overview of Dictionaries}

    63 \label{sec-2}

    64 

    65 \begin{itemize}

    66 \item A dictionary contains meaning of words

    67 

    68 \begin{itemize}

    69 \item \emph{Word} is the \emph{key} here.

    70 \item \emph{Meaning} is the \emph{value} here.

    71 \end{itemize}

    72 

    73 \item A Key-Value pair data structure

    74 

    75 \begin{itemize}

    76 \item Provide key-value mappings

    77 \end{itemize}

    78 

    79 \end{itemize}

    80 \end{frame}

    81 \begin{frame}[fragile]

    82 \frametitle{Creating dictionary}

    83 \label{sec-3}

    84 

    85 \begin{itemize}

    86 \item Empty dictionary

    87 

    88 \begin{itemize}

    89 \item \texttt{mt\_dict = \{\}}

    90 

    91 \begin{itemize}

    92 \item \texttt{[]} - lists

    93 \item \texttt{\{\}} - dictionaries

    94 \end{itemize}

    95 

    96 \end{itemize}

    97 

    98 \item With data

    99 \begin{verbatim}

   100 extensions = {'jpg' : 'JPEG Image', 

   101               'py' : 'Python script',

   102               'html' : 'Html document', 

   103               'pdf' : 'Portable Document Format'}

   104 \end{verbatim}

   105 

   106    \textbf{Note} - ordering in dictionaries cannot be relied on

   107 \end{itemize}

   108 \end{frame}

   109 \begin{frame}[fragile]

   110 \frametitle{Accessing Elements}

   111 \label{sec-4}

   112 

   113 \begin{itemize}

   114 \item syntax

   115 \begin{verbatim}

   116      extensions[key]

   117 \end{verbatim}

   118 

   119 \end{itemize}

   120 

   121   

   122 \begin{verbatim}

   123    In []: print extensions['jpg']

   124    Out []: JPEG Image

   125    In []: print extensions['zip']

   126 \end{verbatim}

   127 \end{frame}

   128 \begin{frame}[fragile]

   129 \frametitle{Adding and Deleting values}

   130 \label{sec-5}

   131 

   132 \begin{itemize}

   133 \item Adding a new value

   134 \begin{verbatim}

   135      In []: extension['cpp'] = 'C++ code'

   136 \end{verbatim}

   137 

   138     adds a new key \emph{cpp} with \emph{C++ code} as value

   139 \item Deleting values

   140 \begin{verbatim}

   141      In []: del extensions['pdf']

   142 \end{verbatim}

   143 

   144     deletes the key-value pair identified by \emph{pdf}

   145 \item Changing value associated with a key

   146 \begin{verbatim}

   147      In []: extension['cpp'] = 'C++ source code'

   148 \end{verbatim}

   149 

   150     changes the value of the existing key

   151 \end{itemize}

   152 \end{frame}

   153 \begin{frame}[fragile]

   154 \frametitle{Checking for container-ship of keys}

   155 \label{sec-6}

   156 

   157 \begin{verbatim}

   158    In []: 'py' in extensions

   159    Out []: True

   160 \end{verbatim}

   161 

   162   Returns \textbf{True} if the \emph{key} is found.

   163 \begin{verbatim}

   164    In []: 'odt' in extensions

   165    Out []: False

   166 \end{verbatim}

   167 

   168   Returns \textbf{False} if the \emph{key} is not found.

   169 \end{frame}

   170 \begin{frame}[fragile]

   171 \frametitle{Retrieve keys and values}

   172 \label{sec-7}

   173 

   174 \begin{itemize}

   175 \item \texttt{.keys()} method

   176 \begin{verbatim}

   177      In []: extensions.keys()

   178 \end{verbatim}

   179 

   180     Returns a list of keys in the dictionary.

   181 \item \texttt{.values()} method

   182 \begin{verbatim}

   183      In []: extensions.values()

   184 \end{verbatim}

   185 

   186     Returns the list of values in the dictionary.

   187 \end{itemize}

   188 \end{frame}

   189 \begin{frame}

   190 \frametitle{Exercise 1}

   191 \label{sec-8}

   192 

   193   Print the keys and values in the dictionary one by one.

   194 \end{frame}

   195 \begin{frame}

   196 \frametitle{Summary}

   197 \label{sec-9}

   198 

   199 \begin{itemize}

   200 \item Creating dictionaries

   201 

   202 \begin{itemize}

   203 \item empty dictionaries

   204 \item with data

   205 \end{itemize}

   206 

   207 \item \texttt{.keys()} method

   208 \item \texttt{.values()} method

   209 \item Iterating over dictionaries

   210 \end{itemize}

   211 \end{frame}

   212 \begin{frame}

   213 \frametitle{Thank you!}

   214 \label{sec-10}

   215 

   216   \begin{block}{}

   217   \begin{center}

   218   This spoken tutorial has been produced by the

   219   \textcolor{blue}{FOSSEE} team, which is funded by the 

   220   \end{center}

   221   \begin{center}

   222     \textcolor{blue}{National Mission on Education through \\

   223       Information \& Communication Technology \\ 

   224       MHRD, Govt. of India}.

   225   \end{center}  

   226   \end{block}

   227 \end{frame}

   228 

   229 \end{document}