Transcription
A Practical Introduction toPython ProgrammingBrian HeinoldDepartment of Mathematics and Computer ScienceMount St. Mary’s University
ii 2012 Brian HeinoldLicensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License
ContentsIBasics11Getting Started1.1 Installing Python1.2 IDLE . . . . . . . .1.3 A first program .1.4 Typing things in .1.5 Getting input . . .1.6 Printing . . . . . .1.7 Variables . . . . .1.8 Exercises . . . . .234.333456679For loops2.1 Examples . . . . . . .2.2 The loop variable . .2.3 The range function2.4 A Trickier Example .2.5 Exercises . . . . . . .111113131415.Numbers3.1 Integers and Decimal Numbers3.2 Math Operators . . . . . . . . . . .3.3 Order of operations . . . . . . . .3.4 Random numbers . . . . . . . . .3.5 Math functions . . . . . . . . . . .3.6 Getting help from Python . . . .3.7 Using the Shell as a Calculator .3.8 Exercises . . . . . . . . . . . . . . .191919212121222223If statements4.1 A Simple Example . .4.2 Conditional operators4.3 Common Mistakes . .4.4 elif . . . . . . . . . . .4.5 Exercises . . . . . . . .272728282930.iii
iv5678CONTENTSMiscellaneous Topics I5.1 Counting . . . . . .5.2 Summing . . . . . .5.3 Swapping . . . . . .5.4 Flag variables . . .5.5 Maxes and mins . .5.6 Comments . . . . .5.7 Simple debugging5.8 Example programs5.9 Exercises . . . . . .Strings6.1 Basics . . . . . . . . . . . . . . . . . . . . . . . . .6.2 Concatenation and repetition . . . . . . . . .6.3 The in operator . . . . . . . . . . . . . . . . . .6.4 Indexing . . . . . . . . . . . . . . . . . . . . . . .6.5 Slices . . . . . . . . . . . . . . . . . . . . . . . . .6.6 Changing individual characters of a string6.7 Looping . . . . . . . . . . . . . . . . . . . . . . .6.8 String methods . . . . . . . . . . . . . . . . . .6.9 Escape characters . . . . . . . . . . . . . . . . .6.10 Examples . . . . . . . . . . . . . . . . . . . . . .6.11 Exercises . . . . . . . . . . . . . . . . . . . . . .Lists7.1 Basics . . . . . . . . . . .7.2 Similarities to strings7.3 Built-in functions . . .7.4 List methods . . . . . .7.5 Miscellaneous . . . . .7.6 Examples . . . . . . . .7.7 Exercises . . . . . . . .More with Lists8.1 Lists and the random module8.2 split . . . . . . . . . . . . . . . .8.3 join . . . . . . . . . . . . . . . . .8.4 List comprehensions . . . . . . .8.5 Using list comprehensions . . .8.6 Two-dimensional lists . . . . . .8.7 Exercises . . . . . . . . . . . . . 7585959606062.6565666768697072
CONTENTS9vWhile loops9.1 Examples . . . . . . . . . . . . . . . . . . .9.2 Infinite loops . . . . . . . . . . . . . . . . .9.3 The break statement . . . . . . . . . . .9.4 The else statement . . . . . . . . . . . . .9.5 The guessing game, more nicely done9.6 Exercises . . . . . . . . . . . . . . . . . . .10 Miscellaneous Topics II10.1 str, int, float, and list10.2 Booleans . . . . . . . . . . . . . . .10.3 Shortcuts . . . . . . . . . . . . . .10.4 Short-circuiting . . . . . . . . . .10.5 Continuation . . . . . . . . . . . .10.6 pass . . . . . . . . . . . . . . . . .10.7 String formatting . . . . . . . . .10.8 Nested loops . . . . . . . . . . . .10.9 Exercises . . . . . . . . . . . . . .75757878798083.8787899091919192939511 Dictionaries11.1 Basics . . . . . . . . . . . . . .11.2 Dictionary examples . . . .11.3 Working with dictionaries11.4 Counting words . . . . . . .11.5 Exercises . . . . . . . . . . .999910010110210412 Text Files12.1 Reading from files12.2 Writing to files . . .12.3 Examples . . . . . .12.4 Wordplay . . . . . .12.5 Exercises . . . . . .10910911011011111313 Functions13.1 Basics . . . . . . . . . . . . . . . . . . . . . . . . . .13.2 Arguments . . . . . . . . . . . . . . . . . . . . . .13.3 Returning values . . . . . . . . . . . . . . . . . .13.4 Default arguments and keyword arguments13.5 Local variables . . . . . . . . . . . . . . . . . . .13.6 Exercises . . . . . . . . . . . . . . . . . . . . . . .11911912012112212312514 Object-Oriented Programming14.1 Python is objected-oriented14.2 Creating your own classes .14.3 Inheritance . . . . . . . . . . .14.4 A playing-card example . .129129130132133.
viCONTENTS14.5 A Tic-tac-toe example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13614.6 Further topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13814.7 Exercises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138IIGraphics15 GUI Programming with Tkinter15.1 Basics . . . . . . . . . . . . . . .15.2 Labels . . . . . . . . . . . . . .15.3 grid . . . . . . . . . . . . . . .15.4 Entry boxes . . . . . . . . . . .15.5 Buttons . . . . . . . . . . . . .15.6 Global variables . . . . . . . .15.7 Tic-tac-toe . . . . . . . . . . . .141.14314314414514614614814916 GUI Programming II16.1 Frames . . . . . . . . . . . . . . . . . .16.2 Colors . . . . . . . . . . . . . . . . . .16.3 Images . . . . . . . . . . . . . . . . . .16.4 Canvases . . . . . . . . . . . . . . . .16.5 Check buttons and Radio buttons16.6 Text widget . . . . . . . . . . . . . .16.7 Scale widget . . . . . . . . . . . . .16.8 GUI Events . . . . . . . . . . . . . . .16.9 Event examples . . . . . . . . . . . .15515515615715815916016116216417 GUI Programming III17.1 Title bar . . . . . . . . . . . . . .17.2 Disabling things . . . . . . . . .17.3 Getting the state of a widget .17.4 Message boxes . . . . . . . . . .17.5 Destroying things . . . . . . . .17.6 Updating . . . . . . . . . . . . .17.7 Dialogs . . . . . . . . . . . . . .17.8 Menu bars . . . . . . . . . . . .17.9 New windows . . . . . . . . . .17.10 pack . . . . . . . . . . . . . . . .17.11 StringVar . . . . . . . . . . .17.12More with GUIs . . . . . . . . .169169169169170171171172174174175175176.18 Further Graphical Programming17718.1 Python 2 vs Python 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17718.2 The Python Imaging Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17918.3 Pygame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
CONTENTSIIIviiIntermediate Topics18319 Miscellaneous topics III19.1 Mutability and References . . . . . . . . . . . . . . . . . .19.2 Tuples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.3 Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.4 Unicode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.5 sorted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.6 if-else operator . . . . . . . . . . . . . . . . . . . . . . .19.7 continue . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.8 eval and exec . . . . . . . . . . . . . . . . . . . . . . . .19.9 enumerate and zip . . . . . . . . . . . . . . . . . . . .19.10 copy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19.11More with strings . . . . . . . . . . . . . . . . . . . . . . . .19.12Miscellaneous tips and tricks . . . . . . . . . . . . . . . .19.13Running your Python programs on other 9620 Useful modules20.1 Importing modules . . . . . . . . . .20.2 Dates and times . . . . . . . . . . . . .20.3 Working with files and directories .20.4 Running and quitting programs . .20.5 Zip files . . . . . . . . . . . . . . . . . .20.6 Getting files from the internet . . . .20.7 Sound . . . . . . . . . . . . . . . . . . .20.8 Your own modules . . . . . . . . . . .19919920020220420420520520621 Regular expressions21.1 Introduction . .21.2 Syntax . . . . . .21.3 Summary . . . .21.4 Groups . . . . . .21.5 Other functions21.6 Examples . . . .20720720821221421421622 Math22.1 The math module . . . . . . . . . . .22.2 Scientific notation . . . . . . . . . . .22.3 Comparing floating point numbers22.4 Fractions . . . . . . . . . . . . . . . . .22.5 The decimal module . . . . . . . .22.6 Complex numbers . . . . . . . . . . .22.7 More with lists and arrays . . . . . .22.8 Random numbers . . . . . . . . . . .22.9 Miscellaneous topics . . . . . . . . . .219219220221221222224226226228.
22.01.2021 · Go towww.python.organd download the latest version of Python (version 3.5 as of this writing). It should be painless to install. If you have a Mac or Linux, you may already have Python on your computer, though it may be an older version. If it is version 2.7 or earlier, then you should install 3
