# HG changeset patch # User Madhusudan.C.S # Date 1256713679 -19800 # Node ID c6704d4a18bddd48674baca8d8c1edd303c7618a # Parent 298cd56f4d5aa86dc0bff57415b013aeda4aa05e Removed multiplication of list with * operator. diff -r 298cd56f4d5a -r c6704d4a18bd day1/session3.tex --- a/day1/session3.tex Tue Oct 27 19:36:09 2009 +0530 +++ b/day1/session3.tex Wed Oct 28 12:37:59 2009 +0530 @@ -317,30 +317,14 @@ from scipy import mean, median, std from scipy import stats -scores = [[]] * 5 -ninety_percents = [{}] * 5 +scores = [[], [], [], [], []] +ninety_percents = [{}, {}, {}, {}, {}] \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{Building data for all subjects \ldots} \begin{lstlisting} -from pylab import pie -from scipy import mean, median, std -from scipy import stats - \end{lstlisting} - - \begin{block}{Repeating list items} - \begin{lstlisting} -scores = [[]] * 5 -ninety_percents = [{}] * 5 - \end{lstlisting} - \end{block} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Building data for all subjects \ldots} - \begin{lstlisting} for record in open('sslc1.txt'): record = record.strip() fields = record.split(';') diff -r 298cd56f4d5a -r c6704d4a18bd day2/session1.tex --- a/day2/session1.tex Tue Oct 27 19:36:09 2009 +0530 +++ b/day2/session1.tex Wed Oct 28 12:37:59 2009 +0530 @@ -140,13 +140,13 @@ \begin{itemize} \item \kwrd{int}\\ Any whole number is an \kwrd{int}, no matter what the size! \begin{lstlisting} -In []: a = 13 +In [1]: a = 13 -In []: a = 99999999999999999999 +In [2]: b = 99999999999999999999 \end{lstlisting} \item \kwrd{float} \begin{lstlisting} -In []: fl = 3.141592 +In [3]: fl = 3.141592 \end{lstlisting} \end{itemize} \end{frame} @@ -154,89 +154,243 @@ \begin{frame}[fragile] \frametitle{Complex numbers} \begin{lstlisting} -In []: cplx = 3+4j +In [1]: cplx = 3+4j -In []: abs(cplx) -Out[]: 5.0 +In [2]: abs(cplx) +Out[2]: 5.0 -In []: cplx.imag -Out[]: 4.0 +In [3]: cplx.imag +Out[3]: 4.0 -In []: cplx.real -Out[]: 3.0 +In [4]: cplx.real +Out[4]: 3.0 \end{lstlisting} \end{frame} \subsection{Boolean} -\begin{frame}{Boolean} - \begin{itemize} - \item \kwrd{True} - \item \kwrd{False} - \item \kwrd{not} - \item \kwrd{and} - \item \kwrd{or} - \end{itemize} +\begin{frame}[fragile] + \frametitle{Boolean} + \begin{lstlisting} +In [1]: t = True + +In [2]: f = not t +Out[2]: False + +In [3]: f or t +Out[3]: True + +In [4]: f and t +Out[4]: False + \end{lstlisting} \end{frame} \subsection{Strings} + \begin{frame}[fragile] - \frametitle{String methods} + \frametitle{Strings} Strings were introduced previously, let us now look at them in a little more detail. \begin{lstlisting} -In []: a = 'hello world' +In [1]: w = "hello" + +In [2]: print w[0] + w[2] + w[-1] +Out[2]: hlo + +In [3]: len(w) # guess what +Out[3]: 5 + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile] + \frametitle{Strings \ldots} + \begin{lstlisting} +In [1]: w[0] = 'H' # Can't do that! +-------------------------------------------- +TypeError Traceback (most recent call last) + +/ in () -In []: a.startswith('hell') -Out[]: True +TypeError: 'str' object does not + support item assignment + \end{lstlisting} +\end{frame} -In []: a.endswith('ld') -Out[]: True +\begin{frame}[fragile] + \frametitle{String methods} + \begin{lstlisting} +In [1]: a = 'Hello World' +In [2]: a.startswith('Hell') +Out[2]: True + +In [3]: a.endswith('ld') +Out[3]: True + +In [4]: a.upper() +Out[4]: 'HELLO WORLD' + +In [5]: a.lower() +Out[5]: 'hello world' \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{Still with strings} -We saw split() previously. join() is the opposite of split() + \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 [1]: ''.join(['a', 'b', 'c']) +Out[1]: 'abc' \end{lstlisting} - \begin{block}{Note:} -Strings are immutable.\\ That is string variables cannot be changed. - \end{block} \end{frame} \begin{frame}[fragile] \frametitle{String formatting} \begin{lstlisting} -In []: x, y = 1, 1.234 -In []: 'x is %s, y is %s' %(x, y) -Out[]: 'x is 1, y is 1.234' +In [1]: x, y = 1, 1.234 + +In [2]: 'x is %s, y is %s' %(x, y) +Out[2]: 'x is 1, y is 1.234' \end{lstlisting} - \small -\url{docs.python.org/lib/typesseq-strings.html}\\ +\emphbar{ +\url{http://docs.python.org/library/stdtypes.html}\\ +} \inctime{10} \end{frame} -\section{Relational and logical operators} +\section{Operators} +\begin{frame}[fragile] + \frametitle{Arithematic operators} + \begin{lstlisting} +In [1]: 1786 % 12 +Out[1]: 10 + +In [2]: 3124 * 126789 +Out[2]: 396088836 + +In [3]: a = 3124 * 126789 + +In [4]: big = 1234567891234567890 ** 3 + +In [5]: verybig = big * big * big * big + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile] + \frametitle{Arithematic operators \ldots} + \begin{lstlisting} +In [1]: 17/2 +Out[1]: 8 + +In [2]: 17/2.0 +Out[2]: 8.5 + +In [3]: 17.0/2 +Out[3]: 8.5 + +In [4]: 17.0/8.5 +Out[4]: 2.0 + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile] + \frametitle{String operations} + \begin{lstlisting} +In [1]: s = 'Hello ' + +In [2]: p = 'World' + +In [3]: s + p +Out[3]: 'Hello World' + +In [4]: s * 12 +Out[4]: 'Hello Hello Hello Hello ...' + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile] + \frametitle{String operations \ldots} + \begin{lstlisting} +In [1]: s * s +-------------------------------------------- +TypeError Traceback (most recent call last) + +/ in () + +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 []: pos, zer, neg = 1, 0, -1 -In []: pos == neg -Out[]: False +In [1]: pos, zer, neg = 1, 0, -1 +In [2]: pos == neg +Out[2]: False -In []: pos >= neg -Out[]: True +In [3]: pos >= neg +Out[3]: True -In []: neg < zer < pos -Out[]: True +In [4]: neg < zer < pos +Out[4]: True -In []: pos + neg != zer -Out[]: False +In [5]: pos + neg != zer +Out[5]: False \end{lstlisting} \inctime{5} \end{frame} +\begin{frame}[fragile] + \frametitle{Built-ins} + \begin{lstlisting} +In [1]: int(17/2.0) +Out[1]: 8 + +In [2]: float(17/2) # Recall +Out[2]: 8.0 + +In [3]: str(17/2.0) +Out[3]: '8.5' + +In [4]: round( 7.5 ) +Out[4]: 8.0 + \end{lstlisting} +\end{frame} + +\begin{frame}[fragile] + \frametitle{Odds and ends} + \begin{itemize} + \item Case sensitive + \item Dynamically typed $\Rightarrow$ need not specify a type + \begin{lstlisting} +In [1]: a = 1 +In [2]: a = 1.1 +In [3]: a = "Now I am a string!" + \end{lstlisting} + \item Comments: + \begin{lstlisting} +In [4]: a = 1 # In-line comments +In [5]: # Comment in a line to itself. +In [6]: a = "# This is not a comment!" + \end{lstlisting} + \end{itemize} + \inctime{15} +\end{frame} + +\begin{frame}[fragile] \frametitle{A question of good style} + \begin{lstlisting} + amount = 12.68 + denom = 0.05 + nCoins = round(amount/denom) + rAmount = nCoins * denom + \end{lstlisting} + \pause + \begin{block}{Style Rule \#1} + Naming is 80\% of programming + \end{block} +\end{frame} + \begin{frame} {A classic problem} \begin{block} @@ -251,6 +405,19 @@ \inctime{10} \end{frame} +\section{Simple IO} +\begin{frame}{Simple IO} + \begin{block} + {Console Input} + \texttt{raw\_input()} waits for user input.\\Prompt string is optional.\\ + All keystrokes are Strings!\\\texttt{int()} converts string to int. + \end{block} + \begin{block} + {Console output} + \texttt{print} is straight forward. Note the distinction between \texttt{print x} and \texttt{print x,} + \end{block} +\end{frame} + \section{Control flow} \begin{frame} \frametitle{Control flow constructs} @@ -279,21 +446,9 @@ \end{lstlisting} \end{frame} -\begin{frame}{Simple IO} - \begin{block} - {Console Input} - \texttt{raw\_input()} waits for user input.\\Prompt string is optional.\\ - All keystrokes are Strings!\\\texttt{int()} converts string to int. - \end{block} - \begin{block} - {Console output} - \texttt{print} is straight forward. Note the distinction between \texttt{print x} and \texttt{print x,} - \end{block} -\end{frame} - \subsection{Basic Looping} \begin{frame}[fragile] - \frametitle{\kwrd{while}} + \frametitle{\typ{while}} Example: Fibonacci series \begin{lstlisting} # the sum of two elements @@ -307,7 +462,7 @@ \end{frame} \begin{frame}[fragile] -\frametitle{\kwrd{range()}} +\frametitle{\typ{range()}} \kwrd{range([start,] stop[, step])}\\ \begin{itemize} \item \alert {range() returns a list of integers} @@ -316,7 +471,7 @@ \end{frame} \begin{frame}[fragile] - \frametitle{\kwrd{for}} + \frametitle{\typ{for} \ldots \typ{range()}} Example: print squares of first \typ{n} numbers \begin{lstlisting} In []: for i in range(5): @@ -389,7 +544,7 @@ \section{Dictionaries} \begin{frame}[fragile] -\frametitle{Dictionaries} +\frametitle{Dictionary: Recall} \alert {lists and tuples: integer indexes :: dictionaries: string indexes} \begin{lstlisting} In []: player = {'Mat': 134,'Inn': 233, @@ -397,20 +552,11 @@ In []: player['Avg'] Out[]: 52.530000000000001 -In []: player.keys() -Out[]: ['Runs', 'Inn', 'Avg', 'Mat'] -In []: player.values() -Out[]: [10823, 233, - 52.530000000000001, 134] \end{lstlisting} -\end{frame} - -\begin{frame}{Dictionaries} \begin{itemize} \item Duplicate keys are not allowed! \item Dictionaries are iterable through keys. \end{itemize} -\inctime{5} \end{frame} \end{document}