|
1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
2 % Tutorial slides on Python. |
|
3 % |
|
4 % Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> |
|
5 % Copyright (c) 2005-2008, Prabhu Ramachandran |
|
6 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
7 |
|
8 \documentclass[14pt,compress]{beamer} |
|
9 %\documentclass[draft]{beamer} |
|
10 %\documentclass[compress,handout]{beamer} |
|
11 %\usepackage{pgfpages} |
|
12 %\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] |
|
13 |
|
14 % Modified from: generic-ornate-15min-45min.de.tex |
|
15 \mode<presentation> |
|
16 { |
|
17 \usetheme{Warsaw} |
|
18 \useoutertheme{split} |
|
19 \setbeamercovered{transparent} |
|
20 } |
|
21 |
|
22 \usepackage[english]{babel} |
|
23 \usepackage[latin1]{inputenc} |
|
24 %\usepackage{times} |
|
25 \usepackage[T1]{fontenc} |
|
26 |
|
27 % Taken from Fernando's slides. |
|
28 \usepackage{ae,aecompl} |
|
29 \usepackage{mathpazo,courier,euler} |
|
30 \usepackage[scaled=.95]{helvet} |
|
31 |
|
32 \definecolor{darkgreen}{rgb}{0,0.5,0} |
|
33 |
|
34 \usepackage{listings} |
|
35 \lstset{language=Python, |
|
36 basicstyle=\ttfamily\bfseries, |
|
37 commentstyle=\color{red}\itshape, |
|
38 stringstyle=\color{darkgreen}, |
|
39 showstringspaces=false, |
|
40 keywordstyle=\color{blue}\bfseries} |
|
41 |
|
42 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
43 % Macros |
|
44 \setbeamercolor{emphbar}{bg=blue!20, fg=black} |
|
45 \newcommand{\emphbar}[1] |
|
46 {\begin{beamercolorbox}[rounded=true]{emphbar} |
|
47 {#1} |
|
48 \end{beamercolorbox} |
|
49 } |
|
50 \newcounter{time} |
|
51 \setcounter{time}{0} |
|
52 \newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}} |
|
53 |
|
54 \newcommand{\typ}[1]{\texttt{#1}} |
|
55 |
|
56 \newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} } |
|
57 |
|
58 %%% This is from Fernando's setup. |
|
59 % \usepackage{color} |
|
60 % \definecolor{orange}{cmyk}{0,0.4,0.8,0.2} |
|
61 % % Use and configure listings package for nicely formatted code |
|
62 % \usepackage{listings} |
|
63 % \lstset{ |
|
64 % language=Python, |
|
65 % basicstyle=\small\ttfamily, |
|
66 % commentstyle=\ttfamily\color{blue}, |
|
67 % stringstyle=\ttfamily\color{orange}, |
|
68 % showstringspaces=false, |
|
69 % breaklines=true, |
|
70 % postbreak = \space\dots |
|
71 % } |
|
72 |
|
73 |
|
74 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
75 % Title page |
|
76 \title[Basic Python]{Python,\\a great programming toolkit:\\ |
|
77 numerics and plotting} |
|
78 |
|
79 \author[Asokan \& Prabhu] {Asokan Pichai\\Prabhu Ramachandran} |
|
80 |
|
81 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} |
|
82 \date[] {26, July 2009} |
|
83 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
84 |
|
85 %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} |
|
86 %\logo{\pgfuseimage{iitmlogo}} |
|
87 |
|
88 |
|
89 %% Delete this, if you do not want the table of contents to pop up at |
|
90 %% the beginning of each subsection: |
|
91 \AtBeginSubsection[] |
|
92 { |
|
93 \begin{frame}<beamer> |
|
94 \frametitle{Outline} |
|
95 \tableofcontents[currentsection,currentsubsection] |
|
96 \end{frame} |
|
97 } |
|
98 |
|
99 \AtBeginSection[] |
|
100 { |
|
101 \begin{frame}<beamer> |
|
102 \frametitle{Outline} |
|
103 \tableofcontents[currentsection,currentsubsection] |
|
104 \end{frame} |
|
105 } |
|
106 |
|
107 % If you wish to uncover everything in a step-wise fashion, uncomment |
|
108 % the following command: |
|
109 %\beamerdefaultoverlayspecification{<+->} |
|
110 |
|
111 %\includeonlyframes{current,current1,current2,current3,current4,current5,current6} |
|
112 |
|
113 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
|
114 % DOCUMENT STARTS |
|
115 \begin{document} |
|
116 |
|
117 \begin{frame} |
|
118 \frametitle{Outline} |
|
119 \tableofcontents |
|
120 \end{frame} |
|
121 \section{Pythonicity} |
|
122 \begin{frame}[fragile] |
|
123 \frametitle{The Zen of Python} |
|
124 |
|
125 Try this! |
|
126 |
|
127 \begin{lstlisting} |
|
128 >>> import this |
|
129 \end{lstlisting} |
|
130 |
|
131 \end{frame} |
|
132 |
|
133 \begin{frame} |
|
134 {Style Guide} |
|
135 |
|
136 Read PEP8 |
|
137 |
|
138 \url{http://www.python.org/dev/peps/pep-0008/} |
|
139 |
|
140 \inctime{10} |
|
141 \end{frame} |
|
142 \section{More Python Machinery} |
|
143 \subsection{Objects} |
|
144 \begin{frame}{Objects in Python} |
|
145 \begin{itemize} |
|
146 \item What is an Object? (Types and classes) |
|
147 \item identity |
|
148 \item type |
|
149 \item method |
|
150 \end{itemize} |
|
151 \end{frame} |
|
152 |
|
153 \begin{frame}[fragile] |
|
154 \frametitle{Why are they useful?} |
|
155 \small |
|
156 \begin{lstlisting} |
|
157 for element in (1, 2, 3): |
|
158 print element |
|
159 for key in {'one':1, 'two':2}: |
|
160 print key |
|
161 for char in "123": |
|
162 print char |
|
163 for line in open("myfile.txt"): |
|
164 print line |
|
165 for line in urllib2.urlopen('http://site.com'): |
|
166 print line |
|
167 \end{lstlisting} |
|
168 \end{frame} |
|
169 \begin{frame}{And the winner is \ldots OBJECTS!} |
|
170 All objects providing a similar inteface can be used the same way.\\ |
|
171 Functions (and others) are first-class objects. Can be passed to and returned from functions. |
|
172 \inctime{10} |
|
173 \end{frame} |
|
174 \subsection{Dictionary} |
|
175 \begin{frame}{Dictionary} |
|
176 \begin{itemize} |
|
177 \item aka associative arrays, key-value pairs, hashmaps, hashtables \ldots |
|
178 \item \typ{ d = \{ ``Hitchhiker's guide'' : 42, ``Terminator'' : ``I'll be back''\}} |
|
179 \item lists and tuples index: 0 \ldots n |
|
180 \item dictionaries index using strings |
|
181 \item aka key-value pairs |
|
182 \item what can be keys? |
|
183 \end{itemize} |
|
184 \end{frame} |
|
185 |
|
186 \begin{frame}{Dict \ldots } |
|
187 \begin{itemize} |
|
188 \item \alert{Unordered} |
|
189 \begin{block}{Standard usage} |
|
190 for key in dict:\\ |
|
191 <use> dict[key] \# => value |
|
192 \end{block} |
|
193 \item \typ{d.keys()} returns a list |
|
194 \item can we have duplicate keys? |
|
195 \end{itemize} |
|
196 \end{frame} |
|
197 \begin{frame} {Problem Set 2.1} |
|
198 \begin{description} |
|
199 \item[2.1.1] You are given date strings of the form ``29, Jul 2009'', or ``4 January 2008''. In other words a number a string and another number, with a comma sometimes separating the items.Write a function that takes such a string and returns a tuple (yyyy, mm, dd) where all three elements are ints. |
|
200 \item[2.1.2] Count word frequencies in a file. |
|
201 \item[2.1.3] Find the most used Python keywords in your Python code (import keyword). |
|
202 \end{description} |
|
203 |
|
204 \inctime{20} |
|
205 \end{frame} |
|
206 |
|
207 \subsection{Set} |
|
208 \begin{frame}[fragile] |
|
209 \frametitle{Set} |
|
210 \begin{itemize} |
|
211 \item Simplest container, mutable |
|
212 \item No ordering, no duplicates |
|
213 \item usual suspects: union, intersection, subset \ldots |
|
214 \item >, >=, <, <=, in, \ldots |
|
215 \end{itemize} |
|
216 \begin{lstlisting} |
|
217 f10 = set([1,2,3,5,8]) |
|
218 p10 = set([2,3,5,7]) |
|
219 f10|p10, f10&p10 |
|
220 f10-p10, p10-f10, f10^p10 |
|
221 set([2,3]) < p10, set([2,3]) <= p10 |
|
222 2 in p10, 4 in p10 |
|
223 len(f10) |
|
224 \end{lstlisting} |
|
225 \end{frame} |
|
226 |
|
227 \begin{frame} |
|
228 \frametitle{Problem set 2.2} |
|
229 \begin{description} |
|
230 \item[2.2.1] Given a dictionary of the names of students and their marks, identify how many duplicate marks are there? and what are these? |
|
231 \item[2.2.2] Given a string of the form ``4-7, 9, 12, 15'' find the numbers missing in this list for a given range. |
|
232 \end{description} |
|
233 \inctime{15} |
|
234 \end{frame} |
|
235 |
|
236 \subsection{Functions Reloaded!} |
|
237 \begin{frame}[fragile] |
|
238 \frametitle{Advanced functions} |
|
239 \begin{itemize} |
|
240 \item default args |
|
241 \item varargs |
|
242 \item keyword args |
|
243 \item scope |
|
244 \item \typ{global} |
|
245 \end{itemize} |
|
246 \end{frame} |
|
247 |
|
248 \begin{frame}[fragile] |
|
249 \frametitle{Functions: default arguments} |
|
250 \begin{lstlisting} |
|
251 def ask_ok(prompt, retries=4, complaint='Yes or no!'): |
|
252 while True: |
|
253 ok = raw_input(prompt) |
|
254 if ok in ('y', 'ye', 'yes'): |
|
255 return True |
|
256 if ok in ('n', 'no', 'nop', 'nope'): |
|
257 return False |
|
258 retries = retries - 1 |
|
259 if retries < 0: |
|
260 raise IOError, 'bad user' |
|
261 print complaint |
|
262 \end{lstlisting} |
|
263 \end{frame} |
|
264 |
|
265 \begin{frame}[fragile] |
|
266 \frametitle{Functions: keyword arguments} |
|
267 \small |
|
268 \begin{lstlisting} |
|
269 def parrot(voltage, state='a stiff', |
|
270 action='voom', type='Royal Blue'): |
|
271 print "-- This parrot wouldn't", action, |
|
272 print "if you supply", voltage, "Volts." |
|
273 print "-- Lovely plumage, the", type |
|
274 print "-- It's", state, "!" |
|
275 |
|
276 parrot(1000) |
|
277 parrot(action = 'VOOOOOM', voltage = 1000000) |
|
278 parrot('a thousand', state = 'pushing up the daisies') |
|
279 parrot('a million', 'bereft of life', 'jump') |
|
280 \end{lstlisting} |
|
281 \end{frame} |
|
282 |
|
283 \begin{frame}[fragile] |
|
284 \frametitle{Functions: arbitrary argument lists} |
|
285 \begin{itemize} |
|
286 \item Arbitrary number of arguments using \verb+*args+ or |
|
287 \verb+*whatever+ |
|
288 \item Keyword arguments using \verb+**kw+ |
|
289 \item Given a tuple/dict how do you call a function? |
|
290 \begin{itemize} |
|
291 \item Using argument unpacking |
|
292 \item For positional arguments: \verb+foo(*[5, 10])+ |
|
293 \item For keyword args: \verb+foo(**{'a':5, 'b':10})+ |
|
294 \end{itemize} |
|
295 \end{itemize} |
|
296 \end{frame} |
|
297 |
|
298 \begin{frame}[fragile] |
|
299 \begin{lstlisting} |
|
300 def foo(a=10, b=100): |
|
301 print a, b |
|
302 def func(*args, **keyword): |
|
303 print args, keyword |
|
304 # Unpacking: |
|
305 args = [5, 10] |
|
306 foo(*args) |
|
307 kw = {'a':5, 'b':10} |
|
308 foo(**kw) |
|
309 \end{lstlisting} |
|
310 \inctime{15} |
|
311 \end{frame} |
|
312 |
|
313 \subsection{Functional programming} |
|
314 \begin{frame}[fragile] |
|
315 \frametitle{Functional programming} |
|
316 What is the basic idea?\\ |
|
317 Why is it interesting?\\ |
|
318 \typ{map, reduce, filter}\\ |
|
319 list comprehension\\ |
|
320 generators |
|
321 \inctime{10} |
|
322 \end{frame} |
|
323 \end{document} |
|
324 |
|
325 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |