% Created 2010-11-12 Fri 02:00

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\usepackage{listings}

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

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

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

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

\title{Testing and debugging}

\author{FOSSEE}

\date{}

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

\begin{document}

\maketitle

\begin{frame}

\frametitle{Outline}

\label{sec-1}

\begin{itemize}

\item What software Testing is?

\item Learn to test simple functions for their functionality.

\item Learn how to automate tests.

\item Need for coding style and some of the standards followed by the Python Community.

\item Handling Errors and Exceptions.

\end{itemize}

\end{frame}

\begin{frame}[fragile]

\frametitle{gcd function}

\label{sec-2}

\begin{itemize}

\item Create gcd.py file with:

\end{itemize}

\begin{verbatim}

def gcd(a, b):

      if a % b == 0: 

          return b

      return gcd(b, a%b)

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Test for gcd.py}

\label{sec-3}

\begin{itemize}

\item Edit gcd.py file

\end{itemize}

\begin{verbatim}

def gcd(a, b):

    if b == 0:

        return a

    return gcd(b, a%b)

if __name__=='__main__':

    result = gcd(48, 64)

    if result != 16:

        print "Test failed"

    print "Test Passed"

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Automating tests}

\label{sec-4}

\begin{verbatim}

if __name=__='__main__':

for line in open('numbers.txt'):

    numbers = line.split()

    x = int(numbers[0])

    y = int(numbers[1])

    result = int(numbers[2])

    if gcd(x, y) != result:

        print "Failed gcd test

                      for", x, y

\end{verbatim}

\end{frame}

\begin{frame}

\frametitle{Question 1}

\label{sec-5}

  For the same inputs as gcd write automated tests for LCM.

\end{frame}

\begin{frame}[fragile]

\frametitle{Solution 1}

\label{sec-6}

\begin{verbatim}

def gcd(a, b):

      if a % b == 0: 

          return b

      return gcd(b, a%b)

 def lcm(a, b):

      return (a * b) / gcd(a, b)

  if __name__ == '__main__':

    for line in open('lcmtestcases.txt'):

      numbers = line.split()

      x = int(numbers[0])

      y = int(numbers[1])

      result = int(numbers[2])

      if lcm(x, y) != result:

          print "Failed lcm test for", x, y

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Meaning full names}

\label{sec-7}

\begin{verbatim}

amount = 12.68

denom = 0.05

nCoins = round(amount / denom)

rAmount = nCoins * denom

\end{verbatim}

\end{frame}

\begin{frame}

\frametitle{Code style}

\label{sec-8}

\begin{itemize}

\item Four Space Indentation

\item 79 character limit on a line

\item Funtions should be seperated by 

   blank line

\item Use Docstring

\item White space around operators

\begin{itemize}

\item l = 32 \% 4

\end{itemize}

\end{itemize}

\end{frame}

\begin{frame}

\frametitle{Question 2}

\label{sec-9}

\begin{itemize}

\item Give meaningful names to the variables in following

     code

\begin{itemize}

\item c = a / b

\end{itemize}

\end{itemize}

\end{frame}

\begin{frame}[fragile]

\frametitle{Solution 2}

\label{sec-10}

\begin{verbatim}

quotient = dividend / divisor

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Code Snippet}

\label{sec-11}

\begin{verbatim}

while True print 'Hello world'

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Error}

\label{sec-12}

\begin{lstlisting}

 while True print 'Hello world'

 \end{lstlisting}

  \begin{lstlisting}

  File "<stdin>", line 1, in ?

    while True print 'Hello world'

SyntaxError: invalid syntax

\end{lstlisting}

\end{frame}

\begin{frame}[fragile]

\frametitle{Code Snippet}

\label{sec-13}

\begin{verbatim}

a = raw_input("Enter a number")

try:

      num = int(a)

 except:

      print "Wrong input ..."

\end{verbatim}

\end{frame}

\begin{frame}[fragile]

\frametitle{Using idb}

\label{sec-14}

\small

\begin{lstlisting}

In []: import mymodule

In []: mymodule.test()

---------------------------------------------

NameError   Traceback (most recent call last)

<ipython console> in <module>()

mymodule.py in test()

      1 def test():

      2     total=1+1

----> 3     print spam

NameError: global name 'spam' is not defined

In []: %debug

> mymodule.py(2)test()

      0     print spam

ipdb> total

2

\end{lstlisting}

\end{frame}

\begin{frame}

\frametitle{Summary}

\label{sec-15}

\begin{itemize}

\item Create simple tests for a function.

\item Learn to Automate tests using many predefined test cases.

\item Good coding standards.

\item Difference between syntax error and exception.

\item Handling exception using try and except.

\item Using \%debug for debugging on ipython.

\end{itemize}

\end{frame}

\begin{frame}

\frametitle{Thank you!}

\label{sec-16}

  \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}