Supercharged Python: Take Your Code to the Next Level

About This eBook
Half Title
Title Page
Copyright Page
Dedication Page
Contents
Preface
What Makes Python Special?
Paths to Learning: Where Do I Start?
Clarity and Examples Are Everything
Learning Aids: Icons
What You’ll Learn
Have Fun
Acknowledgments
About the Authors
1. Review of the Fundamentals
1.1 Python Quick Start
1.2 Variables and Naming Names
1.3 Combined Assignment Operators
1.4 Summary of Python Arithmetic Operators
1.5 Elementary Data Types: Integer and Floating Point
1.6 Basic Input and Output
1.7 Function Definitions
1.8 The Python “if” Statement
1.9 The Python “while” Statement
1.10 A Couple of Cool Little Apps
1.11 Summary of Python Boolean Operators
1.12 Function Arguments and Return Values
1.13 The Forward Reference Problem
1.14 Python Strings
1.15 Python Lists (and a Cool Sorting App)
1.16 The “for” Statement and Ranges
1.17 Tuples
1.18 Dictionaries
1.19 Sets
1.20 Global and Local Variables
Summary
Review Questions
Suggested Problems
2. Advanced String Capabilities
2.1 Strings Are Immutable
2.2 Numeric Conversions, Including Binary
2.3 String Operators (+, =, *, >, etc.)
2.4 Indexing and Slicing
2.5 Single-Character Functions (Character Codes)
2.6 Building Strings Using “join”
2.7 Important String Functions
2.8 Binary, Hex, and Octal Conversion Functions
2.9 Simple Boolean (“is”) Methods
2.10 Case Conversion Methods
2.11 Search-and-Replace Methods
2.12 Breaking Up Input Using “split”
2.13 Stripping
2.14 Justification Methods
Summary
Review Questions
Suggested Problems
3. Advanced List Capabilities
3.1 Creating and Using Python Lists
3.2 Copying Lists Versus Copying List Variables
3.3 Indexing
3.4 Getting Data from Slices
3.5 Assigning into Slices
3.6 List Operators
3.7 Shallow Versus Deep Copying
3.8 List Functions
3.9 List Methods: Modifying a List
3.10 List Methods: Getting Information on Contents
3.11 List Methods: Reorganizing
3.12 Lists as Stacks: RPN Application
3.13 The “reduce” Function
3.14 Lambda Functions
3.15 List Comprehension
3.16 Dictionary and Set Comprehension
3.17 Passing Arguments Through a List
3.18 Multidimensional Lists
Summary
Review Questions
Suggested Problems
4. Shortcuts, Command Line, and Packages
4.1 Overview
4.2 Twenty-Two Programming Shortcuts
4.3 Running Python from the Command Line
4.4 Writing and Using Doc Strings
4.5 Importing Packages
4.6 A Guided Tour of Python Packages
4.7 Functions as First-Class Objects
4.8 Variable-Length Argument Lists
4.9 Decorators and Function Profilers
4.10 Generators
4.11 Accessing Command-Line Arguments
Summary
Questions for Review
Suggested Problems
5. Formatting Text Precisely
5.1 Formatting with the Percent Sign Operator (%)
5.2 Percent Sign (%) Format Specifiers
5.3 Percent Sign (%) Variable-Length Print Fields
5.4 The Global “format” Function
5.5 Introduction to the “format” Method
5.6 Ordering by Position (Name or Number)
5.7 “Repr” Versus String Conversion
5.8 The “spec” Field of the “format” Function and Method
5.9 Variable-Size Fields
Summary
Review Questions
Suggested Problems
6. Regular Expressions, Part I
6.1 Introduction to Regular Expressions
6.2 A Practical Example: Phone Numbers
6.3 Refining Matches
6.4 How Regular Expressions Work: Compiling Versus Running
6.5 Ignoring Case, and Other Function Flags
6.6 Regular Expressions: Basic Syntax Summary
6.7 A Practical Regular-Expression Example
6.8 Using the Match Object
6.9 Searching a String for Patterns
6.10 Iterative Searching (“findall”)
6.11 The “findall” Method and the Grouping Problem
6.12 Searching for Repeated Patterns
6.13 Replacing Text
Summary
Review Questions
Suggested Problems
7. Regular Expressions, Part II
7.1 Summary of Advanced RegEx Grammar
7.2 Noncapture Groups
7.3 Greedy Versus Non-Greedy Matching
7.4 The Look-Ahead Feature
7.5 Checking Multiple Patterns (Look-Ahead)
7.6 Negative Look-Ahead
7.7 Named Groups
7.8 The “re.split” Function
7.9 The Scanner Class and the RPN Project
7.10 RPN: Doing Even More with Scanner
Summary
Review Questions
Suggested Problems
8. Text and Binary Files
8.1 Two Kinds of Files: Text and Binary
8.2 Approaches to Binary Files: A Summary
8.3 The File/Directory System
8.4 Handling File-Opening Exceptions
8.5 Using the “with” Keyword
8.6 Summary of Read/Write Operations
8.7 Text File Operations in Depth
8.8 Using the File Pointer (“seek”)
8.9 Reading Text into the RPN Project
8.10 Direct Binary Read/Write
8.11 Converting Data to Fixed-Length Fields (“struct”)
8.12 Using the Pickling Package
8.13 Using the “shelve” Package
Summary
Review Questions
Suggested Problems
9. Classes and Magic Methods
9.1 Classes and Objects: Basic Syntax
9.2 More About Instance Variables
9.3 The “_ _init_ _” and “_ _new_ _” Methods
9.4 Classes and the Forward Reference Problem
9.5 Methods Generally
9.6 Public and Private Variables and Methods
9.7 Inheritance
9.8 Multiple Inheritance
9.9 Magic Methods, Summarized
9.10 Magic Methods in Detail
9.11 Supporting Multiple Argument Types
9.12 Setting and Getting Attributes Dynamically
Summary
Review Questions
Suggested Problems
10. Decimal, Money, and Other Classes
10.1 Overview of Numeric Classes
10.2 Limitations of Floating-Point Format
10.3 Introducing the Decimal Class
10.4 Special Operations on Decimal Objects
10.5 A Decimal Class Application
10.6 Designing a Money Class
10.7 Writing the Basic Money Class (Containment)
10.8 Displaying Money Objects (“_ _str_ _”, “_ _repr_ _”)
10.9 Other Monetary Operations
10.10 Demo: A Money Calculator
10.11 Setting the Default Currency
10.12 Money and Inheritance
10.13 The Fraction Class
10.14 The Complex Class
Summary
Review Questions
Suggested Problems
11. The Random and Math Packages
11.1 Overview of the Random Package
11.2 A Tour of Random Functions
11.3 Testing Random Behavior
11.4 A Random-Integer Game
11.5 Creating a Deck Object
11.6 Adding Pictograms to the Deck
11.7 Charting a Normal Distribution
11.8 Writing Your Own Random-Number Generator
11.9 Overview of the Math Package
11.10 A Tour of Math Package Functions
11.11 Using Special Values (pi)
11.12 Trig Functions: Height of a Tree
11.13 Logarithms: Number Guessing Revisited
Summary
Review Questions
Suggested Problems
12. The “numpy” (Numeric Python) Package
12.1 Overview of the “array,” “numpy,” and “matplotlib” Packages
12.2 Using the “array” Package
12.3 Downloading and Importing “numpy”
12.4 Introduction to “numpy”: Sum 1 to 1 Million
12.5 Creating “numpy” Arrays
12.6 Example: Creating a Multiplication Table
12.7 Batch Operations on “numpy” Arrays
12.8 Ordering a Slice of “numpy”
12.9 Multidimensional Slicing
12.10 Boolean Arrays: Mask Out That “numpy”!
12.11 “numpy” and the Sieve of Eratosthenes
12.12 Getting “numpy” Stats (Standard Deviation)
12.13 Getting Data on “numpy” Rows and Columns
Summary
Review Questions
Suggested Problems
13. Advanced Uses of “numpy”
13.1 Advanced Math Operations with “numpy”
13.2 Downloading “matplotlib”
13.3 Plotting Lines with “numpy” and “matplotlib”
13.4 Plotting More Than One Line
13.5 Plotting Compound Interest
13.6 Creating Histograms with “matplotlib”
13.7 Circles and the Aspect Ratio
13.8 Creating Pie Charts
13.9 Doing Linear Algebra with “numpy”
13.10 Three-Dimensional Plotting
13.11 “numpy” Financial Applications
13.12 Adjusting Axes with “xticks” and “yticks”
13.13 “numpy” Mixed-Data Records
13.14 Reading and Writing “numpy” Data from Files
Summary
Review Questions
Suggested Problems
14. Multiple Modules and the RPN Example
14.1 Overview of Modules in Python
14.2 Simple Two-Module Example
14.3 Variations on the “import” Statement
14.4 Using the “_ _all_ _” Symbol
14.5 Public and Private Module Variables
14.6 The Main Module and “_ _main_ _”
14.7 Gotcha! Problems with Mutual Importing
14.8 RPN Example: Breaking into Two Modules
14.9 RPN Example: Adding I/O Directives
14.10 Further Changes to the RPN Example
14.11 RPN: Putting It All Together
Summary
Review Questions
Suggested Problems
15. Getting Financial Data off the Internet
15.1 Plan of This Chapter
15.2 Introducing the Pandas Package
15.3 “stock_load”: A Simple Data Reader
15.4 Producing a Simple Stock Chart
15.5 Adding a Title and Legend
15.6 Writing a “makeplot” Function (Refactoring)
15.7 Graphing Two Stocks Together
15.8 Variations: Graphing Other Data
15.9 Limiting the Time Period
15.10 Split Charts: Subplot the Volume
15.11 Adding a Moving-Average Line
15.12 Giving Choices to the User
Summary
Review Questions
Suggested Problems
A. Python Operator Precedence Table
B. Built-In Python Functions
abs(x)
all(iterable)
any(iterable)
ascii(obj)
bin(n)
bool(obj)
bytes(source, encoding)
callable(obj)
chr(n)
compile(cmd_str, filename, mode_str, flags=0, dont_inherit=False, optimize=–1)
complex(real=0, imag=0)
complex(complex_str)
delattr(obj, name_str)
dir([obj])
divmod(a, b)
enumerate(iterable, start=0)
eval(expr_str [, globals [, locals]] )
exec(object [,global [,locals]])
filter(function,iterable)
float([x])
format(obj, [format_spec])
frozenset([iterable])
getattr(obj,name_str [,default])
globals()
hasattr(obj,name_str)
hash(obj)
help([obj])
hex(n)
id(obj)
input([prompt_str])
int(x,base=10)
int()
isinstance(obj,class)
issubclass(class1,class2)
iter(obj)
len(sequence)
list([iterable])
locals()
map(function,iterable1 [,iterable2...])
max(arg1 [, arg2]...)
max(iterable)
min(arg1 [, arg2]...)
min(iterable)
oct(n)
open(file_name_str,mode=‘rt’)
ord(char_str)
pow(x,y [,z])
print(objects,sep=‘‘,end=‘\n‘,file=sys.stdout)
range(n)
range(start,stop [,step])
repr(obj)
reversed(iterable)
round(x [,ndigits])
set([iterable])
setattr(obj,name_str,value)
sorted(iterable [,key] [,reverse])
str(obj=‘‘)
str(obj=b‘‘ [,encoding=‘utf-8‘])
sum(iterable [,start])
super(type)
tuple([iterable])
type(obj)
zip(*iterables)
C. Set Methods
set_obj.add(obj)
set_obj.clear()
set_obj.copy()
set_obj.difference(other_set)
set_obj.difference_update(other_set)
set_obj.discard(obj)
set_obj.intersection(other_set)
set_obj.intersection_update(other_set)
set_obj.isdisjoint(other_set)
set_obj.issubset(other_set)
set_obj.issuperset(other_set)
set_obj.pop()
set_obj.remove(obj)
set_obj.symmetric_difference(other_set)
set_obj.symmetric_difference_update(other_set)
set_obj.union(other_set)
set_obj.union_update(other_set)
D. Dictionary Methods
dict_obj.clear()
dict_obj.copy()
dict_obj.get(key_obj, default_val = None)
dict_obj.items()
dict_obj.keys()
dict_obj.pop(key [,default_value])
dict_obj.popitem()
dict_obj.setdefault(key,default_value=None)
dict_obj.values()
dict_obj.update(sequence)
E. Statement Reference
Variables and Assignments
Spacing Issues in Python
Alphabetical Statement Reference
Index
Code Snippets