Begin to code with Python

656 Pages·2018·6.073 MB·english

by  Rob Miles

Begin
to Code
with
Python
Rob Miles
BEGIN TO CODE WITH PYTHON
Published with the authorization of Microsoft Corporation by:
Pearson Education, Inc.
Copyright © 2018 by Pearson Education, Inc.
ISBN-13: 978-1-5093-0452-3
ISBN-10: 1-5093-0452-5
Library of Congress Control Number: 2017958202
1 17
Contents at a glance
Part 1: Programming fundamentals
Chapter 1 Starting with Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Chapter 2 Python and Programming .......................... 16
Chapter 3 Python program structure .......................... 44
Chapter 4 Working with variables ............................. 72
Chapter 5 Making decisions in programs ...................... 104
Chapter 6 Repeating actions with loops ....................... 140
Chapter 7 Using functions to simplify programs ............... 170
Chapter 8 Storing collections of data ......................... 210
Part 2: Advanced programming
Chapter 9 Use classes to store data .......................... 264
Chapter 10 Use classes to create active objects ................. 308
Chapter 11 Object-based solution design ...................... 372
Chapter 12 Python applications ............................... 438
Part 3: Useful Python (Digital-only)
The chapter PDF files for this Part are available at
https://aka.ms/BeginCodePython/downloads.
Chapter 13 Python and Graphical User Interfaces .............. 488
Chapter 14 Python programs as network clients ............... 548
Chapter 15 Python programs as network servers ................ 570
Chapter 16 Create games with Pygame ........................ 592
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii
Part 1: Programming fundamentals
1
Starting with Python . . . . . . . . . . . . . . . . . . . . . . . . . . 2
What is Python? ............................................... 4
Python origins ......................................... 5
Python versions ....................................... 5
Build a place to work with Python .............................. 6
Get the tools .......................................... 6
Python for Windows PC ................................ 7
Start Python ................................................. 10
What you have learned ....................................... 14
2
Python and Programming . . . . . . . . . . . . . . . . . . . . . 16
What makes a programmer ................................... 18
Programming and party planning ..................... 18
Programming and problems .......................... 19
Programmers and people ............................. 21
Computers as data processors ................................. 22
Machines and computers and us ....................... 22
Programs as data processors .......................... 24
Python as a data processor ............................ 25
Data and information ......................................... 31
Work with Python functions ................................... 36
The ord function ..................................... 36
The chr function ..................................... 38
Investigate data storage using bin ..................... 39
What you have learned ....................................... 41
3
Python program structure . . . . . . . . . . . . . . . . . . . . 44
Write your first Python program ............................... 46
Run Python programs using IDLE ...................... 46
Get program output using the print function ......... 51
Use Python libraries .......................................... 57
The random library ................................... 57
The time library ...................................... 60
Python comments ............................................ 61
Code samples and comments ......................... 62
Run Python from the desktop ................................. 63
Delay the end of the program ......................... 64
Adding some snaps ........................................... 64
Adding the Pygame library ............................ 65
Snaps functions ....................................... 66
What you have learned ....................................... 70
4
Working with variables . . . . . . . . . . . . . . . . . . . . . . . 72
Variables in Python ........................................... 74
Python names ........................................ 76
Working with text ............................................ 79
Marking the start and end of strings ................... 81
Escape characters in text .............................. 82
Read in text using the input function .................. 84
Working with numbers ........................................ 87
Convert strings into integer values ..................... 87
Whole numbers and real numbers ..................... 89
Real numbers and floating-point numbers ............. 90
Convert strings into floating-point values .............. 95
Perform calculations .................................. 96
Convert between float and int ...................... 98
Weather snaps .............................................. 101
What you have learned ...................................... 102
5
Making decisions in programs . . . . . . . . . . . . . . . . 104
Boolean data ................................................ 106
Create Boolean variables ............................. 106
Boolean expressions ................................. 109
Comparing values .................................... 111
Boolean operations .................................. 114
The if construction ......................................... 118
Nesting if conditions ................................ 127
Working with logic .................................. 128
Use decisions to make an application ......................... 129
Design the user interface ............................. 129
Implement a user interface ........................... 130
Testing user input ................................... 132
Complete the program .............................. 133
Input snaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
What you have learned ...................................... 138
6
Repeating actions with loops . . . . . . . . . . . . . . . . . 140
The while construction ...................................... 142
Repeat a sequence of statements using while ........ 142
Handling invalid user entry ........................... 147
Detect invalid number entry using exceptions ......... 152
Exceptions and number reading ...................... 154
Handling multiple exceptions ......................... 156
Break out of loops ................................... 157
Return to the top of a loop with continue ............ 158
Count a repeating loop .............................. 159
The for loop construction ................................... 162
Make a digital clock using snaps .............................. 167
What you have learned ...................................... 168
7
Using functions to simplify programs . . . . . . . . . . 170
What makes a function? ...................................... 172
Give information to functions using parameters ....... 176
Return values from function calls ..................... 185
Build reusable functions ..................................... 193
Create a text input function .......................... 193
Add help information to functions .................... 195
Create a number input function ...................... 197
Convert our functions into a Python module .......... 201
Use the IDLE debugger .............................. 202
What you have learned ...................................... 208
8
Storing collections of data . . . . . . . . . . . . . . . . . . . 210
Lists and tracking sales ....................................... 212
Limitations of individual variables ..................... 214
Lists in Python ....................................... 215
Read in a list ......................................... 218
Display a list using a for loop ........................ 219
Refactor programs into functions ............................. 221
Create placeholder functions ......................... 224
Create a user menu .................................. 225
Sort using bubble sort ....................................... 227
Initialize a list with test data .......................... 228
Sort a list from high to low ........................... 228
Sort a list from low to high ........................... 234
Find the highest and lowest sales values ............... 235
Evaluate total and average sales ...................... 236
Complete the program ............................... 237
Store data in a file ........................................... 238
Write into a file ...................................... 239
Write the sales figures ................................ 242
Read from a file ...................................... 244
Read the sales figures ................................ 246
Deal with file errors .................................. 247
Store tables of data .......................................... 251
Use loops to work with tables ......................... 253
Use lists as lookup tables ..................................... 255
Tuples ...................................................... 256
What you have learned ...................................... 259
Part 2: Advanced programming
9
Use classes to store data . . . . . . . . . . . . . . . . . . . . . 264
Make a tiny contacts app ..................................... 266
Make a prototype ................................... 267
Store contact details in separate lists .................. 269
Use a class to store contact details .................... 272
Use the Contact class in the Tiny
Contacts program ................................... 275
Edit contacts ........................................ 278
Save contacts in a file using pickle .................... 289
Load contacts from a file using pickle ................. 292
Add save and load to Tiny Contacts ................. 293
Set up class instances ................................ 294
Dictionaries ................................................. 300
Create a dictionary .................................. 300
Dictionary management ............................. 302
Return a dictionary from a function ................... 303
Use a dictionary to store contacts ..................... 303
What you have learned ...................................... 305
10
Use classes to create active objects . . . . . . . . . . . 308
Create a Time Tracker ........................................ 310
Add a data attribute to a class ........................ 311
Create a cohesive object ............................. 312
Create method attributes for a class ................... 314
Add validation to methods ........................... 316
Protect a data attribute against damage .............. 328
Protected methods .................................. 331
Create class properties ....................................... 332
Evolve class design ........................................... 337
Manage class versions ............................... 340
The __str__ method in a class ............................... 346
Python string formatting ............................. 348
Session tracking in Time Tracker .............................. 350
The Python map function ............................. 355
The Python join method ............................ 361
Make music with Snaps ...................................... 363
What you have learned ...................................... 368
11
Object-based solution design . . . . . . . . . . . . . . . . 372
Fashion Shop application ..................................... 374
Application data design .............................. 376
Object-oriented design .............................. 376
Creating superclasses and subclasses .................. 379
Data design recap ................................... 396
Implement application behaviors ..................... 405
Objects as components .............................. 409
Create a FashionShop component ........................... 410
Create a user interface component ................... 417