diff -r 8d61625510b6 -r a130a1f494c3 dictionaries/slides.tex --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/dictionaries/slides.tex Mon Oct 11 23:03:49 2010 +0530 @@ -0,0 +1,229 @@ +% Created 2010-10-11 Mon 23:02 +\documentclass[presentation]{beamer} +\usepackage[latin1]{inputenc} +\usepackage[T1]{fontenc} +\usepackage{fixltx2e} +\usepackage{graphicx} +\usepackage{longtable} +\usepackage{float} +\usepackage{wrapfig} +\usepackage{soul} +\usepackage{t1enc} +\usepackage{textcomp} +\usepackage{marvosym} +\usepackage{wasysym} +\usepackage{latexsym} +\usepackage{amssymb} +\usepackage{hyperref} +\tolerance=1000 +\usepackage[english]{babel} \usepackage{ae,aecompl} +\usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet} +\usepackage{listings} +\lstset{language=Python, basicstyle=\ttfamily\bfseries, +commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen}, +showstringspaces=false, keywordstyle=\color{blue}\bfseries} +\providecommand{\alert}[1]{\textbf{#1}} + +\title{Dictionaries} +\author{FOSSEE} +\date{} + +\usetheme{Warsaw}\usecolortheme{default}\useoutertheme{infolines}\setbeamercovered{transparent} +\begin{document} + +\maketitle + + + + + + + + + +\begin{frame} +\frametitle{Outline} +\label{sec-1} + +\begin{itemize} +\item Creating dictionaries + +\begin{itemize} +\item empty dictionaries +\item with data +\end{itemize} + +\item Keys and values +\item Checking for elements +\item Iterating over elements +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Overview of Dictionaries} +\label{sec-2} + +\begin{itemize} +\item A dictionary contains meaning of words + +\begin{itemize} +\item \emph{Word} is the \emph{key} here. +\item \emph{Meaning} is the \emph{value} here. +\end{itemize} + +\item A Key-Value pair data structure + +\begin{itemize} +\item Provide key-value mappings +\end{itemize} + +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Creating dictionary} +\label{sec-3} + +\begin{itemize} +\item Empty dictionary + +\begin{itemize} +\item \texttt{mt\_dict = \{\}} + +\begin{itemize} +\item \texttt{[]} - lists +\item \texttt{\{\}} - dictionaries +\end{itemize} + +\end{itemize} + +\item With data +\begin{verbatim} +extensions = {'jpg' : 'JPEG Image', + 'py' : 'Python script', + 'html' : 'Html document', + 'pdf' : 'Portable Document Format'} +\end{verbatim} + + \textbf{Note} - ordering in dictionaries cannot be relied on +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Accessing Elements} +\label{sec-4} + +\begin{itemize} +\item syntax +\begin{verbatim} + extensions[key] +\end{verbatim} + +\end{itemize} + + +\begin{verbatim} + In []: print extensions['jpg'] + Out []: JPEG Image + In []: print extensions['zip'] +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{Adding and Deleting values} +\label{sec-5} + +\begin{itemize} +\item Adding a new value +\begin{verbatim} + In []: extension['cpp'] = 'C++ code' +\end{verbatim} + + adds a new key \emph{cpp} with \emph{C++ code} as value +\item Deleting values +\begin{verbatim} + In []: del extensions['pdf'] +\end{verbatim} + + deletes the key-value pair identified by \emph{pdf} +\item Changing value associated with a key +\begin{verbatim} + In []: extension['cpp'] = 'C++ source code' +\end{verbatim} + + changes the value of the existing key +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Checking for container-ship of keys} +\label{sec-6} + +\begin{verbatim} + In []: 'py' in extensions + Out []: True +\end{verbatim} + + Returns \textbf{True} if the \emph{key} is found. +\begin{verbatim} + In []: 'odt' in extensions + Out []: False +\end{verbatim} + + Returns \textbf{False} if the \emph{key} is not found. +\end{frame} +\begin{frame}[fragile] +\frametitle{Retrieve keys and values} +\label{sec-7} + +\begin{itemize} +\item \texttt{.keys()} method +\begin{verbatim} + In []: extensions.keys() +\end{verbatim} + + Returns a list of keys in the dictionary. +\item \texttt{.values()} method +\begin{verbatim} + In []: extensions.values() +\end{verbatim} + + Returns the list of values in the dictionary. +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Exercise 1} +\label{sec-8} + + Print the keys and values in the dictionary one by one. +\end{frame} +\begin{frame} +\frametitle{Summary} +\label{sec-9} + +\begin{itemize} +\item Creating dictionaries + +\begin{itemize} +\item empty dictionaries +\item with data +\end{itemize} + +\item \texttt{.keys()} method +\item \texttt{.values()} method +\item Iterating over dictionaries +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Thank you!} +\label{sec-10} + + \begin{block}{} + \begin{center} + This spoken tutorial has been produced by the + \textcolor{blue}{FOSSEE} team, which is funded by the + \end{center} + \begin{center} + \textcolor{blue}{National Mission on Education through \\ + Information \& Communication Technology \\ + MHRD, Govt. of India}. + \end{center} + \end{block} +\end{frame} + +\end{document}