Introduction to Computing Using Python: An Application Development Focus

510 Pages·2012·2.9 MB·English

by  Ljubomir Perkovic

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Introduction to Computing
Using Python
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Introduction to Computing
Using Python
An Application Development Focus
Ljubomir Perkovic
DePaul University
VPANDEXECUTIVEPUBLISHER DonFowley
EXECUTIVEEDITOR BethLangGolub
PROJECTLEAD SamanthaMandel
EDITORIALPROGRAMASSISTANT ElizabethMills
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Contents
Preface
xvii
1
Introduction to Computer Science
1
1.1 Computer Science . . . . . . . . . . . . . . . . . . . 2
WhatDoComputingProfessionalsDo? . . . . . . . . . . 2
Models,Algorithms,andPrograms. . . . . . . . . . . . 3
ToolsoftheTrade . . . . . . . . . . . . . . . . . 3
WhatIsComputerScience?. . . . . . . . . . . . . . 4
1.2 Computer Systems. . . . . . . . . . . . . . . . . . . 4
ComputerHardware . . . . . . . . . . . . . . . . 4
OperatingSystems . . . . . . . . . . . . . . . . . 5
NetworksandNetworkProtocols . . . . . . . . . . . . 6
ProgrammingLanguages. . . . . . . . . . . . . . . 7
SoftwareLibraries . . . . . . . . . . . . . . . . . 7
1.3 Python Programming Language . . . . . . . . . . . . . 8
ShortHistoryofPython . . . . . . . . . . . . . . . 8
SettingUpthePythonDevelopmentEnvironment. . . . . . . 8
1.4 Computational Thinking . . . . . . . . . . . . . . . . . 9
ASampleProblem . . . . . . . . . . . . . . . . . 9
AbstractionandModeling. . . . . . . . . . . . . . . 10
Algorithm . . . . . . . . . . . . . . . . . . . . 10
DataTypes . . . . . . . . . . . . . . . . . . . 11
AssignmentsandExecutionControlStructures . . . . . . . 12
Chapter Summary . . . . . . . . . . . . . . . . . . . . . 13
vii
viii Contents
2
Python Data Types
15
2.1 Expressions, Variables, and Assignments. . . . . . . . . . 16
AlgebraicExpressionsandFunctions. . . . . . . . . . . 16
BooleanExpressionsandOperators . . . . . . . . . . . 18
VariablesandAssignments . . . . . . . . . . . . . . 20
VariableNames . . . . . . . . . . . . . . . . . . 22
2.2 Strings. . . . . . . . . . . . . . . . . . . . . . . . 23
StringOperators. . . . . . . . . . . . . . . . . . 23
IndexingOperator . . . . . . . . . . . . . . . . . 25
2.3 Lists. . . . . . . . . . . . . . . . . . . . . . . . . 27
ListOperators . . . . . . . . . . . . . . . . . . 27
ListsAreMutable,StringsAreNot . . . . . . . . . . . . 29
ListMethods . . . . . . . . . . . . . . . . . . . 29
2.4 Objects and Classes . . . . . . . . . . . . . . . . . . 31
ObjectType . . . . . . . . . . . . . . . . . . . 32
ValidValuesforNumberTypes . . . . . . . . . . . . . 33
OperatorsforNumberTypes. . . . . . . . . . . . . . 34
CreatingObjects. . . . . . . . . . . . . . . . . . 35
ImplicitTypeConversions. . . . . . . . . . . . . . . 36
ExplicitTypeConversions. . . . . . . . . . . . . . . 37
ClassMethodsandObject-OrientedProgramming . . . . . . 38
2.5 Python Standard Library. . . . . . . . . . . . . . . . . 39
Modulemath . . . . . . . . . . . . . . . . . . . 39
Modulefractions. . . . . . . . . . . . . . . . . 40
2.6 Case Study: Turtle Graphics Objects. . . . . . . . . . . . 41
Chapter Summary . . . . . . . . . . . . . . . . . . . . . 45
Solutions to Practice Problems. . . . . . . . . . . . . . . . 46
Exercises . . . . . . . . . . . . . . . . . . . . . . . . 48
3
Imperative Programming
53
3.1 Python Programs . . . . . . . . . . . . . . . . . . . 54
OurFirstPythonProgram. . . . . . . . . . . . . . . 54
PythonModules . . . . . . . . . . . . . . . . . . 56
Built-InFunctionprint() . . . . . . . . . . . . . . 56
InteractiveInputwithinput() . . . . . . . . . . . . . 57
Functioneval(). . . . . . . . . . . . . . . . . . 58