Workshop materials: comparison day2/session1.tex

equal deleted inserted replaced

-:dc8d666a594a
+:49e10e9fc660
 }
 \newcounter{time}
 \setcounter{time}{0}
 \newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}}
-\newcommand{\typ}[1]{\lstinline{#1}}
+\newcommand{\typ}[1]{\textbf{\texttt{{#1}}}}
 \newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}}  }
 %%% This is from Fernando's setup.
 \title[Basic Python]{Python language: Basics}
 \author[FOSSEE Team] {The FOSSEE Group}
 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
-\date[] {SciPy 2010, Introductory tutorials\\Day 2, Session 1}
+\date[] {SciPy.in 2010, Tutorials}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
 %\logo{\pgfuseimage{iitmlogo}}
 \end{lstlisting}
 \item \kwrd{float}
 \begin{lstlisting}
 In []: p = 3.141592
 \end{lstlisting}
-\end{itemize}
+\item \kwrd{complex}
-\end{frame}
-\begin{frame}[fragile]
-\frametitle{Complex numbers}
 \begin{lstlisting}
 In []: c = 3+4j
+\end{lstlisting}
-In []: abs(c)
+\end{itemize}
-Out[]: 5.0
-In []: c.imag
-Out[]: 4.0
-In []: c.real
-Out[]: 3.0
-\end{lstlisting}
 \end{frame}
 \subsection{Booleans}
 \begin{frame}[fragile]
 \frametitle{Booleans}
 Out[]: True
 In []: F and t
 Out[]: False
 \end{lstlisting}
-\inctime{5}
+%%  \inctime{5}
 \end{frame}
 \begin{frame}[fragile]
 \frametitle{( )  for precedence}
 \begin{lstlisting}
 Out[]: True
 In []: a and (b or c)
 Out[]: False
 \end{lstlisting}
-\inctime{5}
+%%  \inctime{5}
 \end{frame}
 \subsection{Strings}
 \begin{frame}[fragile]
+\frametitle{Strings}
+Anything within ``quotes'' is a string!
+\begin{lstlisting}
+' This is a string '
+" This too! "
+""" This one too! """
+''' And one more! '''
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Strings}
+Why so many?
+\begin{lstlisting}
+' "Do or do not.  No try." said Yoda.'
+" ' is a mighty lonely quote."
+\end{lstlisting}
+The triple quoted ones can span multiple lines!
+\begin{lstlisting}
+""" The quick brown
+fox jumped over
+the lazy dingbat.
+"""
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
 \frametitle{Strings}
-Strings were introduced previously, let us now look at them in a little more detail.
 \begin{lstlisting}
 In []: w = "hello"
-In []: print w[0] + w[2] + w[-1]
+In []: print w[0], w[1], w[-1]
-Out[]: hlo
 In []: len(w)
 Out[]: 5
 \end{lstlisting}
 \end{frame}
 <ipython console> in <module>()
 TypeError: 'str' object does not
 support item assignment
+\end{lstlisting}
+\end{frame}
+\section{Operators}
+\begin{frame}[fragile]
+\frametitle{Arithmetic operators}
+\small
+\begin{lstlisting}
+In []: 1786 % 12
+Out[]: 10
+In []: 45 % 2
+Out[]: 1
+In []: 864675 % 10
+Out[]: 5
+In []: 3124 * 126789
+Out[]: 396088836
+In []: big = 1234567891234567890 ** 3
+In []: verybig = big * big * big * big
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Arithmetic operators}
+\begin{lstlisting}
+In []: 17 / 2
+Out[]: 8
+In []: 17 / 2.0
+Out[]: 8.5
+In []: 17.0 / 2
+Out[]: 8.5
+In []: 17.0 / 8.5
+Out[]: 2.0
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Arithmetic operators}
+\begin{lstlisting}
+In []: c = 3+4j
+In []: abs(c)
+Out[]: 5.0
+In []: c.imag
+Out[]: 4.0
+In []: c.real
+Out[]: 3.0
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Arithmetic operators}
+\begin{lstlisting}
+In []: a = 7546
+In []: a += 1
+In []: a
+Out[]: 7547
+In []: a -= 5
+In []: a
+In []: a *= 2
+In []: a /= 5
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{String operations}
+\begin{lstlisting}
+In []: s = 'Hello'
+In []: p = 'World'
+In []: s + p
+Out[]: 'HelloWorld'
+In []: s * 4
+Out[]: 'HelloHelloHelloHello'
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{String operations \ldots}
+\begin{lstlisting}
+In []: s * s
+\end{lstlisting}
+\pause
+\begin{lstlisting}
+--------------------------------------------
+TypeError  Traceback (most recent call last)
+<ipython console> in <module>()
+TypeError: can`t multiply sequence by
+non-int of type `str`
 \end{lstlisting}
 \end{frame}
 \begin{frame}[fragile]
 \frametitle{String methods}
 Out[]: 'hello world'
 \end{lstlisting}
 \end{frame}
 \begin{frame}[fragile]
-\frametitle{A bit about IPython}
+\frametitle{Strings: \typ{split} \& \typ{join}}
-Recall, we showed a few features of IPython, here is one more:
+\begin{lstlisting}
-\begin{itemize}
+In []: chars = 'a b c'
-\item IPython provides better help
+In []: chars.split()
-\item object.function?
+Out[]: ['a', 'b', 'c']
-\begin{lstlisting}
+In []: ' '.join(['a', 'b', 'c'])
-In []: a = 'Hello World'
+Out[]: 'a b c'
-In []: a.lower?
+\end{lstlisting}
-\end{lstlisting}
-\end{itemize}
+\begin{lstlisting}
-\end{frame}
+In []: alpha = ', '.join(['a', 'b', 'c'])
+In []: alpha
-\begin{frame}[fragile]
-\frametitle{Still with strings}
-\begin{itemize}
-\item We saw split() yesterday
-\item join() is the opposite of split()
-\end{itemize}
-\begin{lstlisting}
-In []: ''.join(['a', 'b', 'c'])
-Out[]: 'abc'
-In []: ', '.join(['a', 'b', 'c'])
 Out[]: 'a, b, c'
+In []: alpha.split(', ')
+Out[]: ['a', 'b', 'c']
 \end{lstlisting}
 \end{frame}
 \begin{frame}[fragile]
 \frametitle{String formatting}
 \end{lstlisting}
 \begin{itemize}
 \item \emph{\%d}, \emph{\%f} etc. available
 \end{itemize}
 \emphbar{\url{http://docs.python.org/library/stdtypes.html}}
-\inctime{10}
+%%  \inctime{10}
-\end{frame}
-\section{Operators}
-\begin{frame}[fragile]
-\frametitle{Arithmetic operators}
-\small
-\begin{lstlisting}
-In []: 1786 % 12
-Out[]: 10
-In []: 45 % 2
-Out[]: 1
-In []: 864675 % 10
-Out[]: 5
-In []: 3124 * 126789
-Out[]: 396088836
-In []: big = 1234567891234567890 ** 3
-In []: verybig = big * big * big * big
-\end{lstlisting}
-\end{frame}
-\begin{frame}[fragile]
-\frametitle{Arithmetic operators}
-\begin{lstlisting}
-In []: 17 / 2
-Out[]: 8
-In []: 17 / 2.0
-Out[]: 8.5
-In []: 17.0 / 2
-Out[]: 8.5
-In []: 17.0 / 8.5
-Out[]: 2.0
-\end{lstlisting}
-\end{frame}
-\begin{frame}[fragile]
-\frametitle{Arithmetic operators}
-\begin{lstlisting}
-In []: a = 7546
-In []: a += 1
-In []: a
-Out[]: 7547
-In []: a -= 5
-In []: a
-In []: a *= 2
-In []: a /= 5
-\end{lstlisting}
-\end{frame}
-\begin{frame}[fragile]
-\frametitle{String operations}
-\begin{lstlisting}
-In []: s = 'Hello'
-In []: p = 'World'
-In []: s + p
-Out[]: 'HelloWorld'
-In []: s * 4
-Out[]: 'HelloHelloHelloHello'
-\end{lstlisting}
-\end{frame}
-\begin{frame}[fragile]
-\frametitle{String operations \ldots}
-\begin{lstlisting}
-In []: s * s
-\end{lstlisting}
-\pause
-\begin{lstlisting}
---------------------------------------------
-TypeError  Traceback (most recent call last)
-<ipython console> in <module>()
-TypeError: can`t multiply sequence by
-non-int of type `str`
-\end{lstlisting}
 \end{frame}
 \begin{frame}[fragile]
 \frametitle{Relational and logical operators}
 \begin{lstlisting}
 In []: a = 1  # In-line comments
 In []: # A comment line.
 In []: a = "# Not a comment!"
 \end{lstlisting}
 \end{itemize}
-\inctime{15}
+%%  \inctime{15}
 \end{frame}
 \section{Simple IO}
 \begin{frame}[fragile]
 \frametitle{Simple IO: Console Input}
 In []: a = raw_input('Enter a value: ')
 Enter a value: 5
 \end{lstlisting}
 \item Prompt string is optional.
 \item All keystrokes are strings!
-\item \texttt{int()} converts string to int.
+\item \typ{int()} converts string to int.
 \end{itemize}
 \end{frame}
 \begin{frame}[fragile]
 \frametitle{Simple IO: Console output}
 \section{Control flow}
 \begin{frame}
 \frametitle{Control flow constructs}
 \begin{itemize}
 \item \kwrd{if/elif/else}: branching
-\item \kwrd{C if X else D}: Ternary conditional operator
 \item \kwrd{while}: looping
 \item \kwrd{for}: iterating
 \item \kwrd{break, continue}: modify loop
 \item \kwrd{pass}: syntactic filler
 \end{itemize}
 \end{frame}
 \subsection{Basic Conditional flow}
 \begin{frame}[fragile]
-\frametitle{\typ{If...elif...else} example}
+\frametitle{\typ{if...elif...else} example}
 Type the following code in an editor \& save as \alert{ladder.py}
 \small
 \begin{lstlisting}
 x = int(raw_input("Enter an integer:"))
 if x < 0:
 print 'Single'
 else:
 print 'More'
 \end{lstlisting}
-\inctime{10}
+%%  \inctime{10}
 \end{frame}
-\begin{frame}[fragile]
+\section{Control flow}
-\frametitle{Ternary conditional operator}
+\subsection{Basic Looping}
-\begin{lstlisting}
+\begin{frame}[fragile]
-...
+\frametitle{\typ{while}}
-a = raw_input('Enter number(Q to quit):')
+\begin{block}{Example: Fibonacci series}
-num = int(a) if a != 'Q' else 0
+Sum of previous two elements defines the next
-...
+\end{block}
-\end{lstlisting}
+\begin{lstlisting}
-\end{frame}
+In []: a, b = 0, 1
+In []: while b < 10:
+...:     print b,
+...:     a, b = b, a + b
+...:
+...:
+\end{lstlisting}
+\typ{1 1 2 3 5 8}\\
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{\typ{range()}}
+\kwrd{range([start,] stop[, step])}\\
+\begin{itemize}
+\item \typ{range()} returns a list of integers
+\item The \typ{start} and the \typ{step} arguments are optional
+\item \typ{stop} is not included in the list
+\end{itemize}
+\vspace*{.5in}
+\begin{block}{Documentation convention}
+\begin{itemize}
+\item \alert{Anything within \typ{[]} is optional}
+\item Nothing to do with Python.
+\end{itemize}
+\end{block}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{\typ{for} \ldots \typ{range()}}
+Example: print squares of first \typ{5} numbers
+\begin{lstlisting}
+In []: for i in range(5):
+....:     print i, i * i
+....:
+....:
+0 0
+1 1
+2 4
+3 9
+4 16
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{\typ{for} \ldots \typ{range()}}
+Example: print squares of odd numbers from 3 to 9
+\begin{lstlisting}
+In []: for i in range(3, 10, 2):
+....:     print i, i * i
+....:
+....:
+3 9
+5 25
+7 49
+9 81
+\end{lstlisting}
+%% \inctime{5}
+\end{frame}
+\subsection{Exercises}
+\begin{frame}{Problem 1.1: \emph{Armstrong} numbers}
+Write a program that displays all three digit numbers that are equal to the sum of the cubes of their digits. That is, print numbers $abc$ that have the property $abc = a^3 + b^3 + c^3$\\
+For example, $153 = 1^3 + 5^3 + 3^3$\\
+\vspace*{0.2in}
+\end{frame}
+\begin{frame}{Problem 1.2: Collatz sequence}
+\begin{enumerate}
+\item Start with an arbitrary (positive) integer.
+\item If the number is even, divide by 2; if the number is odd, multiply by 3 and add 1.
+\item Repeat the procedure with the new number.
+\item It appears that for all starting values there is a cycle of 4, 2, 1 at which the procedure loops.
+\end{enumerate}
+Write a program that accepts the starting value and prints out the Collatz sequence.
+%% \inctime{5}
+\end{frame}
 \begin{frame}[fragile]
 \frametitle{What did we learn?}
 \begin{itemize}
 \item Data types: int, float, complex, boolean, string
 \item Operators: +, -, *, /, \%, **, +=, -=, *=, /=, >, <, <=, >=, ==, !=, a < b < c
 \item Simple IO: \kwrd{raw\_input} and \kwrd{print}
-\item Conditional structures: \kwrd{if/elif/else},\\ \kwrd{C if X else D}
+\item Conditionals: \kwrd{if elif else}
+\item Looping: \kwrd{while} \& \kwrd{for}
 \end{itemize}
 \end{frame}
 \end{document}

branch	scipyin2010
changeset 449	49e10e9fc660
parent 420	5e408de16a14