Programming in Python 3: A Complete Introduction to the Python Language

644 Pages·2010·2.54 MB·English

by  Mark Summerfield

Programming in Python 3
A Complete Introduction to the Python Language
Second Edition
ptg
Mark Summerfield
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Libraryof CongressCataloging-in-PublicationData
Summerfield,Mark.
ProgramminginPython3:acompleteintroductiontothePythonlanguage/Mark
Summerfield.—2nded.
p. cm. ptg
Includesbibliographicalreferencesandindex.
ISBN978-0-321-68056-3 (pbk.:alk. paper)
1. Python(Computerprogramlanguage) 2. Object-orientedprogramming(Computerscience)
I. Title.
QA76.73.P98S86 2010
005.13’3—dc22
2009035430
Copyright©2010PearsonEducation,Inc.
All rights reserved. Printed in the United States of America. This publication is protected by
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ISBN-13: 978-0-321-68056-3
ISBN-10: 0-321-68056-1
TextprintedintheUnitedStatesonrecycledpaperatRRDonnelleyinCrawfordsville,Indiana.
Firstprinting,November2009
From the Library of STEPHEN EISEMAN
Inmemory of
FrancoRabaiotti
1961–2001
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From the Library of STEPHEN EISEMAN
Contents at a Glance
Listof Tables ...................................................... xv
Introduction ...................................................... 1
Chapter1. RapidIntroductiontoProceduralProgramming ... 9
Chapter2. DataTypes ............................................ 51
Chapter3. CollectionDataTypes ................................ 107
Chapter4. ControlStructuresandFunctions ................... 159
Chapter5. Modules ...............................................195
Chapter6. Object-OrientedProgramming ...................... 233
Chapter7. FileHandling ......................................... 287
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Chapter8. AdvancedProgrammingTechniques ................ 339
Chapter9. Debugging,Testing,andProfiling ................... 413
Chapter10. ProcessesandThreading ........................... 439
Chapter11. Networking ..........................................457
Chapter12. DatabaseProgramming ............................. 475
Chapter13. RegularExpressions ................................ 489
Chapter14. IntroductiontoParsing ............................. 513
Chapter15. IntroductiontoGUIProgramming ................. 569
Epilogue ...........................................................595
SelectedBibliography ............................................ 597
Index .............................................................. 599
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From the Library of STEPHEN EISEMAN
Contents
Listof Tables ..................................................... xv
Introduction ...................................................... 1
Chapter1. RapidIntroductiontoProceduralProgramming ... 9
CreatingandRunningPythonPrograms ........................ 9
Python’s“BeautifulHeart” ...................................... 14
Piece#1:DataTypes ....................................... 14
Piece#2:ObjectReferences ................................. 16
Piece#3:CollectionDataTypes ............................. 18
Piece#4:LogicalOperations ................................ 21
Piece#5:ControlFlowStatements .......................... 26
Piece#6:ArithmeticOperators .............................. 30
Piece#7:Input/Output ..................................... 33
Piece#8:CreatingandCallingFunctions .................... 36
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Examples ...................................................... 39
bigdigits.py ................................................ 39
generate_grid.py ........................................... 42
Summary ...................................................... 44
Exercises ...................................................... 47
Chapter2. DataTypes ........................................... 51
IdentifiersandKeywords ....................................... 51
IntegralTypes.................................................. 54
Integers ................................................... 54
Booleans ................................................... 58
Floating-PointTypes ........................................... 58
Floating-PointNumbers .................................... 59
ComplexNumbers ......................................... 62
DecimalNumbers .......................................... 63
Strings......................................................... 65
ComparingStrings ......................................... 68
SlicingandStridingStrings ................................ 69
StringOperatorsandMethods .............................. 71
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StringFormattingwiththestr.format()Method .............. 78
CharacterEncodings ....................................... 91
Examples ...................................................... 94
quadratic.py ............................................... 94
csv2html.py ................................................ 97
Summary ...................................................... 102
Exercises ...................................................... 104
Chapter3. CollectionDataTypes ................................ 107
SequenceTypes ................................................ 107
Tuples ..................................................... 108
NamedTuples ............................................. 111
Lists....................................................... 113
SetTypes ...................................................... 120
Sets ....................................................... 121
FrozenSets ................................................ 125
MappingTypes ................................................. 126
Dictionaries................................................ 126
DefaultDictionaries ........................................ 135
OrderedDictionaries ....................................... 136
IteratingandCopyingCollections ............................... 138 ptg
IteratorsandIterableOperationsandFunctions ............. 138
CopyingCollections ........................................ 146
Examples ...................................................... 148
generate_usernames.py .................................... 149
statistics.py ................................................ 152
Summary ...................................................... 156
Exercises ...................................................... 158
Chapter4. ControlStructuresandFunctions ................... 159
ControlStructures.............................................. 159
ConditionalBranching ..................................... 159
Looping .................................................... 161
ExceptionHandling ............................................ 163
CatchingandRaisingExceptions ........................... 163
CustomExceptions ......................................... 168
CustomFunctions .............................................. 171
NamesandDocstrings...................................... 176
ArgumentandParameterUnpacking ....................... 177
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From the Library of STEPHEN EISEMAN
AccessingVariablesintheGlobalScope ..................... 180
LambdaFunctions ......................................... 182
Assertions ................................................. 183
Example:make_html_skeleton.py ............................... 185
Summary ...................................................... 191
Exercise ....................................................... 192
Chapter5. Modules .............................................. 195
ModulesandPackages .......................................... 195
Packages .................................................. 199
CustomModules ........................................... 202
Overviewof Python’sStandardLibrary.......................... 212
StringHandling ........................................... 213
Command-LineProgramming .............................. 214
MathematicsandNumbers ................................. 216
TimesandDates ........................................... 216
AlgorithmsandCollectionDataTypes....................... 217
FileFormats,Encodings,andDataPersistence............... 219
File,Directory,andProcessHandling ........................ 222
NetworkingandInternetProgramming ..................... 225
XML....................................................... 226 ptg
OtherModules ............................................. 228
Summary ...................................................... 230
Exercise ....................................................... 231
Chapter6. Object-OrientedProgramming ...................... 233
TheObject-OrientedApproach .................................. 234
Object-OrientedConceptsandTerminology .................. 235
CustomClasses ................................................ 238
AttributesandMethods .................................... 238
InheritanceandPolymorphism ............................. 243
UsingPropertiestoControlAttributeAccess ................ 246
CreatingCompleteFullyIntegratedDataTypes ............. 248
CustomCollectionClasses ...................................... 261
CreatingClassesThatAggregateCollections ................ 261
CreatingCollectionClassesUsingAggregation .............. 269
CreatingCollectionClassesUsingInheritance............... 276
Summary ...................................................... 283
Exercises ...................................................... 285
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From the Library of STEPHEN EISEMAN
Chapter7. FileHandling ......................................... 287
WritingandReadingBinaryData ............................... 292
PickleswithOptionalCompression.......................... 292
RawBinaryDatawithOptionalCompression ............... 295
WritingandParsingTextFiles .................................. 305
WritingText ............................................... 305
ParsingText ............................................... 307
ParsingTextUsingRegularExpressions .................... 310
WritingandParsingXMLFiles ................................. 312
ElementTrees ............................................. 313
DOM(DocumentObjectModel) ............................. 316
ManuallyWritingXML..................................... 319
ParsingXMLwithSAX(SimpleAPIforXML) ............... 321
RandomAccessBinaryFiles .................................... 324
AGenericBinaryRecordFileClass .......................... 324
Example:TheBikeStockModule’sClasses ................... 332
Summary ...................................................... 336
Exercises ...................................................... 337
Chapter8. AdvancedProgrammingTechniques ................ 339
FurtherProceduralProgramming ............................... 340 ptg
BranchingUsingDictionaries............................... 340
GeneratorExpressionsandFunctions ....................... 341
DynamicCodeExecutionandDynamicImports.............. 344
LocalandRecursiveFunctions .............................. 351
FunctionandMethodDecorators............................ 356
FunctionAnnotations ...................................... 360
FurtherObject-OrientedProgramming .......................... 363
ControllingAttributeAccess ................................ 363
Functors ................................................... 367
ContextManagers.......................................... 369
Descriptors ................................................ 372
ClassDecorators ........................................... 378
AbstractBaseClasses ...................................... 380
MultipleInheritance ....................................... 388
Metaclasses ................................................ 390
Functional-StyleProgramming ................................. 395
PartialFunctionApplication ................................ 398
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Coroutines ................................................. 399
Example:Valid.py .............................................. 407
Summary ...................................................... 410
Exercises ...................................................... 411
Chapter9. Debugging,Testing,andProfiling ................... 413
Debugging ..................................................... 414
DealingwithSyntaxErrors................................. 414
DealingwithRuntimeErrors ............................... 415
ScientificDebugging ....................................... 420
UnitTesting ................................................... 425
Profiling ....................................................... 432
Summary ...................................................... 437
Chapter10. ProcessesandThreading ........................... 439
UsingtheMultiprocessingModule .............................. 440
UsingtheThreadingModule .................................... 444
Example:AThreadedFindWordProgram ................... 446
Example:AThreadedFindDuplicateFilesProgram ......... 449
Summary ...................................................... 454
Exercises ...................................................... 455
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Chapter11. Networking ......................................... 457
CreatingaTCPClient .......................................... 458
CreatingaTCPServer ......................................... 464
Summary ...................................................... 471
Exercises ...................................................... 471
Chapter12. DatabaseProgramming............................. 475
DBMDatabases ................................................ 476
SQLDatabases................................................. 480
Summary ...................................................... 487
Exercise ....................................................... 488
Chapter13. RegularExpressions ................................ 489
Python’sRegularExpressionLanguage .......................... 490
CharactersandCharacterClasses .......................... 490
Quantifiers ................................................ 491
GroupingandCapturing ................................... 494
AssertionsandFlags ....................................... 496
TheRegularExpressionModule................................. 499
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From the Library of STEPHEN EISEMAN