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Diffstat (limited to 'day1/Session-4.tex')
| -rwxr-xr-x | day1/Session-4.tex | 106 |
1 files changed, 58 insertions, 48 deletions
diff --git a/day1/Session-4.tex b/day1/Session-4.tex index e447b00..5aa552c 100755 --- a/day1/Session-4.tex +++ b/day1/Session-4.tex @@ -78,7 +78,7 @@ \author[FOSSEE Team] {Asokan Pichai\\Prabhu Ramachandran} \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {10, October 2009} +\date[] {10, October 2009\\Day 1, Session 4} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} @@ -213,8 +213,7 @@ False \frametitle{Functions: default arguments} \small \begin{lstlisting} -def ask_ok(prompt, retries=4, - complaint='Yes or no!'): +def ask_ok(prompt, complaint='Yes or no!'): while True: ok = raw_input(prompt) if ok in ('y', 'ye', 'yes'): @@ -222,10 +221,10 @@ def ask_ok(prompt, retries=4, if ok in ('n', 'no', 'nop', 'nope'): return False - retries = retries - 1 - if retries < 0: - raise IOError, 'bad user' print complaint + +ask_ok('?') +ask_ok('?', '[Y/N]') \end{lstlisting} \end{frame} @@ -233,49 +232,21 @@ def ask_ok(prompt, retries=4, \frametitle{Functions: keyword arguments} \small \begin{lstlisting} -def parrot(voltage, state='a stiff', - action='voom', type='Royal Blue'): - print "-- This parrot wouldn't", action, - print "if you supply", voltage, "Volts." - print "-- Lovely plumage, the", type - print "-- It's", state, "!" - -parrot(1000) -parrot(action = 'VOOOOOM', voltage = 1000000) -parrot('a thousand', - state = 'pushing up the daisies') -parrot('a million', 'bereft of life', 'jump') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: arbitrary argument lists} - \begin{itemize} - \item Arbitrary number of arguments using \verb+*args+ or - \verb+*whatever+ - \item Keyword arguments using \verb+**kw+ - \item Given a tuple/dict how do you call a function? - \begin{itemize} - \item Using argument unpacking - \item For positional arguments: \verb+foo(*[5, 10])+ - \item For keyword args: \verb+foo(**{'a':5, 'b':10})+ - \end{itemize} - \end{itemize} -\end{frame} +def ask_ok(prompt, complaint='Yes or no!'): + while True: + ok = raw_input(prompt) + if ok in ('y', 'ye', 'yes'): + return True + if ok in ('n', 'no', 'nop', + 'nope'): + return False + print complaint - \begin{frame}[fragile] -\begin{lstlisting} -def foo(a=10, b=100): - print a, b -def func(*args, **keyword): - print args, keyword -# Unpacking: -args = [5, 10] -foo(*args) -kw = {'a':5, 'b':10} -foo(**kw) +ask_ok(prompt='?') +ask_ok(prompt='?', complaint='[Y/N]') +ask_ok(complaint='[Y/N]', prompt='?') \end{lstlisting} - \inctime{15} +\inctime{15} \end{frame} \subsection{Functional programming} @@ -286,9 +257,43 @@ Why is it interesting?\\ \typ{map, reduce, filter}\\ list comprehension\\ generators - \inctime{15} \end{frame} +\begin{frame}[fragile] + \frametitle{List Comprehensions} +Lets say we want to squares of all the numbers from 1 to 100 + \begin{lstlisting} +squares = [] +for i in range(1, 100): + squares.append(i * i) + \end{lstlisting} + \begin{lstlisting} +# list comprehension +squares = [i*i for i in range(1, 100)] + \end{lstlisting} +Which is more readable? +\end{frame} + +\begin{frame}[fragile] + \frametitle{List Comprehensions} +What if you had a more complex function? +Lets say we want squares of numbers from 1 to 100 ending in 1, 2, 5, 7 only + \begin{lstlisting} +squares = [] +for i in range(1, 100): + if i % 10 in [1, 2, 5, 7]: + squares.append(i * i) + \end{lstlisting} + \begin{lstlisting} +# list comprehension +squares = [i*i for i in range(1, 100) + if i % 10 in [1, 2, 5, 7]] + \end{lstlisting} +Which is more readable? +\inctime{15} +\end{frame} + + \subsection{Debugging} \begin{frame}[fragile] \frametitle{Errors} @@ -375,4 +380,9 @@ ipdb> \frametitle{Debugging: Exercise} \end{frame} +\begin{frame} + \frametitle{What did we learn?} + \tableofcontents + % You might wish to add the option [pausesections] +\end{frame} \end{document} |