diff -r 88a01948450d -r d33698326409 getting_started_with_functions/slides.tex --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/getting_started_with_functions/slides.tex Wed Dec 01 16:51:35 2010 +0530 @@ -0,0 +1,318 @@ +% Created 2010-11-10 Wed 18:59 +\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{Getting started with functions} +\author{FOSSEE} +\date{} + +\usetheme{Warsaw}\usecolortheme{default}\useoutertheme{infolines}\setbeamercovered{transparent} +\begin{document} + +\maketitle + + + + + + + + + +\begin{frame} +\frametitle{Outline} +\label{sec-1} + +\begin{itemize} +\item Define functions +\item Pass arguments to functions +\item Learn about docstrings +\item Return values from functions +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Function} +\label{sec-2} + +\begin{itemize} +\item Eliminate code redundancy +\item Help in code reuse +\item Subroutine + +\begin{itemize} +\item relatively independent of remaining code +\end{itemize} + +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{f(x)} a mathematical function} +\label{sec-3} + + + $f(x) = x^{2}$ + +\begin{verbatim} + f(1) -> 1 + f(2) -> 4 +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{Define \texttt{f(x)} in Python} +\label{sec-4} + +\begin{verbatim} +def f(x): + return x*x +\end{verbatim} + +\begin{itemize} +\item \texttt{def} - keyword +\item \texttt{f} - function name +\item \texttt{x} - parameter / argument to function \texttt{f} +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Exercise 1} +\label{sec-5} + + + Write a python function named \texttt{cube} which computes the cube of a given + number \texttt{n}. + +\begin{itemize} +\item Pause here and try to solve the problem yourself. +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Solution} +\label{sec-6} + +\begin{verbatim} +def cube(n): + return n**3 +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{greet} function} +\label{sec-7} + + + Function \texttt{greet} which will print \texttt{Hello World!}. +\begin{verbatim} +def greet(): + print "Hello World!" +\end{verbatim} +\begin{itemize} +\item Call the function \texttt{greet} +\begin{verbatim} + In []: greet() + Hello World! +\end{verbatim} + +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Exercise 2} +\label{sec-8} + + + Write a python function named \texttt{avg} which computes the average of + \texttt{a} and \texttt{b}. + +\begin{itemize} +\item Pause here and try to solve the problem yourself. +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Solution 2} +\label{sec-9} + +\begin{verbatim} +def avg(a,b): + return (a + b)/2 +\end{verbatim} + +\begin{itemize} +\item \texttt{a} and \texttt{b} are parameters +\item \texttt{def f(p1, p2, p3, ... , pn)} +\end{itemize} +\end{frame} +\begin{frame}[fragile] +\frametitle{Docstring} +\label{sec-10} + + +\begin{itemize} +\item Documenting/commenting code is a good practice +\begin{verbatim} +def avg(a,b): + """ avg takes two numbers as input + (a & b), and returns the average + of a and b""" + return (a+b)/2 +\end{verbatim} +\item Docstring + +\begin{itemize} +\item written in the line after the \texttt{def} line. +\item Inside triple quote. +\end{itemize} + +\item Documentation +\begin{verbatim} + avg? +\end{verbatim} + +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Exercise 3} +\label{sec-11} + + Add docstring to the function f. +\end{frame} +\begin{frame}[fragile] +\frametitle{Solution 3} +\label{sec-12} + + +\begin{verbatim} +def f(x): + """Accepts a number x as argument and, + returns the square of the number x.""" + return x*x +\end{verbatim} +\end{frame} +\begin{frame} +\frametitle{Exercise 4} +\label{sec-13} + + Write a python function named \texttt{circle} which returns the area and + perimeter of a circle given radius \texttt{r}. +\end{frame} +\begin{frame}[fragile] +\frametitle{Solution 4} +\label{sec-14} + +\begin{verbatim} +def circle(r): + """returns area and perimeter of a circle given + radius r""" + pi = 3.14 + area = pi * r * r + perimeter = 2 * pi * r + return area, perimeter +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{what}} +\label{sec-15} + +\begin{verbatim} + +def what( n ): + if n < 0: n = -n + while n > 0: + if n % 2 == 1: + return False + n /= 10 + return True +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{even\_digits}} +\label{sec-16} + +\begin{verbatim} +def even_digits( n ): + """returns True if all the digits of number + n is even returns False if all the digits + of number n is not even""" + if n < 0: n = -n + while n > 0: + if n % 2 == 1: + return False + n /= 10 + return True +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{what}} +\label{sec-17} + +\begin{verbatim} +def what( n ): + i = 1 + while i * i < n: + i += 1 + return i * i == n, i +\end{verbatim} +\end{frame} +\begin{frame}[fragile] +\frametitle{\texttt{is\_perfect\_square}} +\label{sec-18} + +\begin{verbatim} +def is_perfect_square( n ): + """returns True and square root of n, + if n is a perfect square, otherwise + returns False and the square root + of the next perfect square""" + i = 1 + while i * i < n: + i += 1 + return i * i == n, i +\end{verbatim} +\end{frame} +\begin{frame} +\frametitle{Summary} +\label{sec-19} + +\begin{itemize} +\item Functions in Python +\item Passing parameters to a function +\item Returning values from a function +\item We also did few code reading exercises. +\end{itemize} +\end{frame} +\begin{frame} +\frametitle{Thank you!} +\label{sec-20} + + \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}