Learn More Python 3 the Hard Way

Preface xiv



Part I: Initial Knowledge 2



Exercise 0: The Setup 6

A Programmer's Editor 6

Python 3.6 6

A Working Terminal 6

A Working pip+virtualenv Configuration 7

Lab Journal 7

A Github.com Account 7

git 7

Optional: Screen-Recording Software 8

Further Study 8



Exercise 1: On Process 10

Exercise Challenge 11

Study Drills 12

Further Study 12



Exercise 2: On Creativity 14

Exercise Challenge 14

Study Drill 15



Exercise 3: On Quality 16

Exercise Challenge 18

Study Drill 18



Part II: Quick Hacks 20

Exercise 4: Dealing with Command Line Arguments 24

Exercise Challenge 24

Solution 25

Study Drills 25



Exercise 5: cat 26

Exercise Challenge 26

Solution 27

Study Drills 27

Further Study 27



Exercise 6: find 28

Exercise Challenge 29

Study Drills 30

Further Study 30



Exercise 7: grep 32

Exercise Challenge 32

Study Drills 33

Further Study 33



Exercise 8: cut 34

Exercise Challenge 35

Study Drill 35

Further Study 35



Exercise 9: sed 36

Exercise Challenge 36

Study Drills 37

Further Study 37



Exercise 10: sort 38

Exercise Challenge 38

Study Drills 39

Further Study 39



Exercise 11: uniq 40

Exercise Challenge 40

Study Drills 41

Further Study 41



Exercise 12: Review 42

Exercise Challenge 42

Study Drills 43

Further Study 43



Part III: Data Structures 46

Exercise 13: Single Linked Lists 50

Description 50

Controller 52

Test 53

Introductory Auditing 55

Exercise Challenge 56

Auditing 56

Study Drill 56



Exercise 14: Double Linked Lists 58

Introducing Invariant Conditions 59

Exercise Challenge 60

Study Drill 61



Exercise 15: Stacks and Queues 62

Exercise Challenge 62

Breaking It 64

Further Study 64



Exercise 16: Bubble, Quick, and Merge Sort 66

Exercise Challenge 66

Study Drills 71



Exercise 17: Dictionary 74

Exercise Challenge 74

Doing a "Code Master Copy" 74

Copy the Code 75

Annotate the Code 78

Summarize the Data Structure 78

Memorize the Summary 79

Implement from Memory 80

Repeat 80

Study Drills 81

Break It 81



Exercise 18: Measuring Performance 82

The Tools 82

Analyzing Performance 84

Exercise Challenge 86

Study Drills 86

Breaking It 86

Further Study 86



Exercise 19: Improving Performance 88

Exercise Challenge 89

Further Study 90



Exercise 20: Binary Search Trees 92

BSTree Requirements 92

Deleting 93

Exercise Challenge 94

Study Drills 94



Exercise 21: Binary Search 96

Exercise Challenge 96

Study Drills 96

Further Study 97



Exercise 22: Suffix Arrays 98

Exercise Challenge 99

Study Drills 99

Further Study 99



Exercise 23: Ternary Search Trees 100

Exercise Challenge 100

Study Drills 102



Exercise 24: Fast URL Search 104

Exercise Challenge 104

Study Drills 105

Further Study 105



Part IV: Intermediate Projects 106



Exercise 25: xargs 108

Exercise Challenge 108

Study Drills 108



Exercise 26: hexdump 110

Exercise Challenge 111

Study Drill 112

Further Study 112



Exercise 27: tr 114

Exercise Challenge 114

A Criticism of 45-Minute Blocks 115

Study Drills 115



Exercise 28: sh 116

Exercise Challenge 116

Study Drill 117

Further Study 117



Exercise 29: diff and patch 118

Exercise Challenge 118

Study Drill 119

Further Study 119



Part V: Parsing Text 120



Exercise 30: Finite State Machines 122

Exercise Challenge 123

Study Drills 125

Further Study 125



Exercise 31: Regular Expressions 126

Exercise Challenge 127

Study Drills 128

Further Study 128



Exercise 32: Scanners 130

Puny Python Scanner 131

Exercise Challenge 133

Study Drills 133

Further Study 133



Exercise 33: Parsers 136

Recursive Descent Parsing 137

BNF Grammars 138

Quick Demo Hack Parser 140

Exercise Challenge 142

Study Drill 142

Further Study 142



Exercise 34: Analyzers 144

Visitor Pattern 144

A Short Puny Python Analyzer 145

Parser versus Analyzer 148

Exercise Challenge 148

Study Drills 149

Further Study 149



Exercise 35: Interpreters 150

Interpreters versus Compilers 150

Python Is Both 151

How to Write an Interpreter 151

Exercise Challenge 152

Study Drills 152

Further Study 152



Exercise 36: Simple Calculator 154

Exercise Challenge 154

Study Drills 155

Further Study 155



Exercise 37: Little BASIC 156

Exercise Challenge 156

Study Drills 157



Part VI: SQL and Object Relational Mapping 158

Exercise 38: Introduction to SQL 160

What Is SQL? 160

The Setup 161

Learning SQL Vocabulary 162

SQL Grammar 163

Further Study 163



Exercise 39: Creating with SQL 164

Creating Tables 164

Creating a Multi-table Database 165

Inserting Data 165

Insert Referential Data 166

Exercise Challenge 166

Further Study 167



Exercise 40: Reading with SQL 168

Select across Many Tables 168

Exercise Challenge 169

Further Study 170



Exercise 41: Updating with SQL 172

Updating Complex Data 172

Replacing Data 173

Exercise Challenge 173

Further Study 174



Exercise 42: Deleting with SQL 176

Deleting Using Other Tables 176

Exercise Challenge 177

Further Study 178



Exercise 43: SQL Administration 180

Destroying and Altering Tables 180

Migrating and Evolving Data 181

Exercise Challenge 182

Further Study 182



Exercise 44: Using Python's Database API 184

Learning an API 184

Exercise Challenge 185

Further Study 185



Exercise 45: Creating an ORM 186

Exercise Challenge 186

Further Study 187



Part VII: Final Projects 188



Exercise 46: blog 190

Exercise Challenge 190

Study Drills 191



Exercise 47: bc 192

Exercise Challenge 192

Study Drill 193



Exercise 48: ed 194

Exercise Challenge 194

Study Drills 195



Exercise 49: sed 196

Exercise Challenge 197

Study Drill 197



Exercise 50: vi 198

Exercise Challenge 198

Study Drills 199



Exercise 51: lessweb 200

Exercise Challenge 200

Breaking It 200

Study Drills 201



Exercise 52: moreweb 202

Exercise Challenge 202

Breaking It 203

Further Study 203



Index 204