The Quick Python Book, Second Edition

Quick Python......Page 1
brief contents......Page 6
contents......Page 8
preface......Page 18
acknowledgments......Page 19
How to use this book......Page 21
Roadmap......Page 22
Code conventions......Page 23
About the author......Page 24
About the cover illustration......Page 25
Part 1 Starting out......Page 26
1.1 Why should I use Python?......Page 28
1.2.2 Python is expressive......Page 29
1.2.3 Python is readable......Page 30
1.2.6 Python is free......Page 31
1.3.1 Python is not the fastest language......Page 32
1.4 Why learn Python 3?......Page 33
1.5 Summary......Page 34
2.1 Installing Python......Page 35
2.2.1 The basic interactive mode......Page 37
2.2.2 The IDLE integrated development environment......Page 38
2.3 Using IDLE’s Python Shell window......Page 39
2.5 Using the interactive prompt to explore Python......Page 40
2.6 Summary......Page 42
3 The Quick Python overview......Page 43
3.2.1 Numbers......Page 44
3.2.2 Lists......Page 46
3.2.3 Tuples......Page 47
3.2.4 Strings......Page 48
3.2.6 Sets......Page 49
3.3.1 Boolean values and expressions......Page 50
3.3.3 The while loop......Page 51
3.3.5 Function definition......Page 52
3.3.6 Exceptions......Page 53
3.4 Module creation......Page 54
3.5 Object-oriented programming......Page 55
3.6 Summary......Page 56
Part 2 The essentials......Page 58
4.1 Indentation and block structuring......Page 60
4.3 Variables and assignments......Page 62
4.4 Expressions......Page 63
4.5 Strings......Page 64
4.6 Numbers......Page 65
4.6.4 Complex numbers......Page 66
4.6.5 Advanced complex-number functions......Page 67
4.10 Basic Python style......Page 68
4.11 Summary......Page 69
5 Lists, tuples, and sets......Page 70
5.2 List indices......Page 71
5.3 Modifying lists......Page 73
5.4 Sorting lists......Page 75
5.4.1 Custom sorting......Page 76
5.5.1 List membership with the in operator......Page 77
5.5.5 List search with index......Page 78
5.5.7 Summary of list operations......Page 79
5.6 Nested lists and deep copies......Page 80
5.7.1 Tuple basics......Page 82
5.7.3 Packing and unpacking tuples......Page 83
5.8.1 Set operations......Page 85
5.8.2 Frozensets......Page 86
5.9 Summary......Page 87
6.1 Strings as sequences of characters......Page 88
6.3 Special characters and escape sequences......Page 89
6.3.2 Numeric (octal and hexadecimal) and Unicode escape sequences......Page 90
6.3.3 Printing vs. evaluating strings with special characters......Page 91
6.4.1 The split and join string methods......Page 92
6.4.2 Converting strings to numbers......Page 93
6.4.3 Getting rid of extra whitespace......Page 94
6.4.4 String searching......Page 95
6.4.5 Modifying strings......Page 96
6.4.7 Useful methods and constants......Page 98
6.5 Converting from objects to strings......Page 99
6.6.2 The format method and named parameters......Page 101
6.7 Formatting strings with %......Page 102
6.7.2 Named parameters and formatting sequences......Page 103
6.9 Summary......Page 105
7 Dictionaries......Page 106
7.1 What is a dictionary?......Page 107
7.2 Other dictionary operations......Page 108
7.4 What can be used as a key?......Page 111
7.6 Dictionaries as caches......Page 113
7.8 Summary......Page 114
8.1 The while loop......Page 115
8.2 The if-elif-else statement......Page 116
8.3 The for loop......Page 117
8.3.1 The range function......Page 118
8.3.4 The enumerate function......Page 119
8.4 List and dictionary comprehensions......Page 120
8.5 Statements, blocks, and indentation......Page 121
8.6.1 Most Python objects can be used as Booleans......Page 124
8.6.2 Comparison and Boolean operators......Page 125
8.7 Writing a simple program to analyze a text file......Page 126
8.8 Summary......Page 127
9.1 Basic function definitions......Page 128
9.2.1 Positional parameters......Page 130
9.2.2 Passing arguments by parameter name......Page 131
9.2.3 Variable numbers of arguments......Page 132
9.3 Mutable objects as arguments......Page 133
9.4 Local, nonlocal, and global variables......Page 134
9.6 lambda expressions......Page 136
9.7 Generator functions......Page 137
9.8 Decorators......Page 138
9.9 Summary......Page 139
10.1 What is a module?......Page 140
10.2 A first module......Page 141
10.4 The module search path......Page 144
10.4.1 Where to place your own modules......Page 145
10.5 Private names in modules......Page 146
10.6 Library and third-party modules......Page 147
10.7 Python scoping rules and namespaces......Page 148
10.8 Summary......Page 153
11 Python programs......Page 154
11.1.1 Starting a script from a command line......Page 155
11.1.3 Redirecting the input and output of a script......Page 156
11.1.4 The optparse module......Page 157
11.1.5 Using the fileinput module......Page 158
11.4 Script execution options in Windows......Page 160
11.4.1 Starting a script as a document or shortcut......Page 161
11.4.3 Starting a script from a command window......Page 162
11.5 Scripts on Windows vs. scripts on UNIX......Page 163
11.6 Programs and modules......Page 165
11.7.3 Creating executable programs with freeze......Page 170
11.8 Summary......Page 171
12 Using the filesystem......Page 172
12.1.1 Absolute and relative paths......Page 173
12.1.2 The current working directory......Page 174
12.1.3 Manipulating pathnames......Page 175
12.1.4 Useful constants and functions......Page 178
12.2 Getting information about files......Page 179
12.3 More filesystem operations......Page 180
12.4 Processing all files in a directory subtree......Page 181
12.5 Summary......Page 182
13.1 Opening files and file objects......Page 184
13.3 Opening files in write or other modes......Page 185
13.4 Functions to read and write text or binary data......Page 186
13.5 Screen input/output and redirection......Page 188
13.6 Reading structured binary data with the struct module......Page 190
13.7 Pickling objects into files......Page 192
13.8 Shelving objects......Page 195
13.9 Summary......Page 196
14 Exceptions......Page 197
14.1.1 General philosophy of errors and exception handling......Page 198
14.1.2 A more formal definition of exceptions......Page 200
14.2 Exceptions in Python......Page 201
14.2.1 Types of Python exceptions......Page 202
14.2.2 Raising exceptions......Page 203
14.2.3 Catching and handling exceptions......Page 204
14.2.4 Defining new exceptions......Page 205
14.2.5 Debugging programs with the assert statement......Page 206
14.2.7 Example: a disk-writing program in Python......Page 207
14.2.8 Example: exceptions in normal evaluation......Page 208
14.3 Using with......Page 209
14.4 Summary......Page 210
15 Classes and object-oriented programming......Page 211
15.1.1 Using a class instance as a structure or record......Page 212
15.3 Methods......Page 213
15.4 Class variables......Page 215
15.4.1 An oddity with class variables......Page 216
15.5.1 Static methods......Page 217
15.5.2 Class methods......Page 218
15.6 Inheritance......Page 219
15.7 Inheritance with class and instance variables......Page 221
15.8 Private variables and private methods......Page 222
15.9 Using @property for more flexible instance variables......Page 223
15.10 Scoping rules and namespaces for class instances......Page 224
15.11 Destructors and memory management......Page 228
15.12 Multiple inheritance......Page 232
15.13 Summary......Page 233
16 Graphical user interfaces......Page 234
16.1 Installing Tkinter......Page 235
16.2 Starting Tk and using Tkinter......Page 236
16.3.2 Named attributes......Page 237
16.3.3 Geometry management and widget placement......Page 238
16.4 A simple Tkinter application......Page 239
16.5 Creating widgets......Page 240
16.6 Widget placement......Page 241
16.7 Using classes to manage Tkinter applications......Page 243
16.8 What else can Tkinter do?......Page 244
16.8.1 Event handling......Page 245
16.9 Alternatives to Tkinter......Page 246
16.10 Summary......Page 247
Part 3 Advanced language features......Page 248
17.1 What is a regular expression?......Page 250
17.2 Regular expressions with special characters......Page 251
17.3 Regular expressions and raw strings......Page 252
17.3.1 Raw strings to the rescue......Page 253
17.4 Extracting matched text from strings......Page 254
17.5 Substituting text with regular expressions......Page 257
17.6 Summary......Page 258
18.1 What is a package?......Page 259
18.2 A first example......Page 260
18.3 A concrete example......Page 261
18.3.1 Basic use of the mathproj package......Page 262
18.3.2 Loading subpackages and submodules......Page 263
18.3.4 __init__.py files in packages......Page 264
18.4 The __all__ attribute......Page 265
18.6 Summary......Page 266
19.1 Types are objects, too......Page 267
19.3 Types and user-defined classes......Page 268
19.4 Duck typing......Page 270
19.5 Summary......Page 271
20 Advanced object-oriented features......Page 272
20.1 What is a special method attribute?......Page 273
20.2.1 The __getitem__ special method attribute......Page 274
20.2.2 How it works......Page 275
20.2.3 Implementing full list functionality......Page 276
20.3 Giving an object full list capability......Page 277
20.4.1 Subclassing list......Page 279
20.4.2 Subclassing UserList......Page 280
20.6 Metaclasses......Page 281
20.7 Abstract base classes......Page 283
20.7.1 Using abstract base classes for type checking......Page 284
20.7.3 Using the @abstractmethod and @abstractproperty decorators......Page 285
20.8 Summary......Page 287
Part 4 Where can you go from here?......Page 288
21.1 Why you need to have tests......Page 290
21.2.1 Python’s __debug__ variable......Page 291
21.3 Tests in docstrings: doctests......Page 292
21.3.2 Tweaking doctests with directives......Page 294
21.4.1 Setting up and running a single test case......Page 295
21.4.3 Running multiple tests......Page 297
21.5 Summary......Page 298
22.1 Porting from 2 to 3......Page 299
22.1.1 Steps in porting from Python 2.x to 3.x......Page 300
22.2 Testing with Python 2.6 and -3......Page 301
22.3 Using 2to3 to convert the code......Page 302
22.4 Testing and common problems......Page 304
22.5.1 Using Python 2.5 or earlier......Page 305
22.6 Summary......Page 306
23.1 “Batteries included”—the standard library......Page 307
23.1.1 Managing various data types......Page 308
23.1.2 Manipulating files and storage......Page 309
23.1.3 Accessing operating system services......Page 310
23.1.5 Development and debugging tools and runtime services......Page 311
23.3 Adding more Python libraries......Page 312
23.4.1 Installing under the home scheme......Page 313
23.6 Summary......Page 314
24 Network, web, and database programming......Page 315
24.1.1 Using the sqlite3 database......Page 316
24.2.1 Creating an instant HTTP server......Page 318
24.2.2 Writing an HTTP client......Page 319
24.3.2 Using the wsgi library to create a basic web app......Page 320
24.3.3 Using frameworks to create advanced web apps......Page 321
24.4.1 Creating the database......Page 322
24.4.3 Adding a form and retrieving its contents......Page 323
24.4.4 Saving the form’s contents......Page 324
24.4.5 Parsing the URL and retrieving messages......Page 325
24.4.6 Adding an HTML wrapper......Page 328
24.5 Summary......Page 329
A guide to Python’s documentation......Page 330
The Python manual of style......Page 333
The Zen of Python......Page 346
A......Page 348
C......Page 349
D......Page 350
F......Page 351
H......Page 352
L......Page 353
N......Page 354
P......Page 355
S......Page 357
T......Page 359
W......Page 360
Z......Page 361
back cover......Page 362