Python 3: The Comprehensive Guide to Hands-On Python Programming

https://www.drcarolineedwards.com/2024/09/18/dddx5pb Dear Reader Notes on Usage Table of Contents 1 Introduction 1.1 Why Did We Write This Book? 1.2 What Does This Book Provide? 1.3 Structure of the Book 1.4 How Should You Read This Book? 1.5 Sample Programs 1.6 Preface To the First English Edition (2022) 1.7 Acknowledgments 2 The Python Programming Language 2.1 History, Concepts, and Areas of Application 2.1.1 History and Origin 2.1.2 Basic Concepts 2.1.3 Possible Areas of Use and Strengths 2.1.4 Examples of Use 2.2 Installing Python 2.2.1 Installing Anaconda on Windows 2.2.2 Installing Anaconda on Linux 2.2.3 Installing Anaconda on macOS 2.3 Installing Third-Party Modules 2.4 Using Python Part I Getting Started with Python 3 Getting Started with the Interactive Mode 3.1 Integers 3.2 Floats 3.3 Character Strings 3.4 Lists 3.5 Dictionaries 3.6 Variables 3.6.1 The Special Meaning of the Underscore 3.6.2 Identifiers 3.7 Logical Expressions 3.8 Functions and Methods 3.8.1 Functions 3.8.2 Methods 3.9 Screen Outputs 3.10 Modules 4 The Path to the First Program 4.1 Typing, Compiling, and Testing 4.1.1 Windows 4.1.2 Linux and macOS 4.1.3 Shebang 4.1.4 Internal Processes 4.2 Basic Structure of a Python Program 4.2.1 Wrapping Long Lines 4.2.2 Joining Multiple Lines 4.3 The First Program 4.3.1 Initialization 4.3.2 Loop Header 4.3.3 Loop Body 4.3.4 Screen Output 4.4 Comments 4.5 In Case of Error 5 Control Structures 5.1 Conditionals 5.1.1 The if Statement 5.1.2 Conditional Expressions 5.2 Loops 5.2.1 The while Loop 5.2.2 Termination of a Loop 5.2.3 Detecting a Loop Break 5.2.4 Aborting the Current Iteration 5.2.5 The for Loop 5.2.6 The for Loop as a Counting Loop 5.3 The pass Statement 5.4 Assignment Expressions 5.4.1 The Guessing Numbers Game with Assignment Expressions 6 Files 6.1 Data Streams 6.2 Reading Data from a File 6.2.1 Opening and Closing a File 6.2.2 The with Statement 6.2.3 Reading the File Content 6.3 Writing Data to a File 6.4 Generating the File Object 6.4.1 The Built-In open Function 6.4.2 Attributes and Methods of a File Object 6.4.3 Changing the Write/Read Position 7 The Data Model 7.1 The Structure of Instances 7.1.1 Data Type 7.1.2 Value 7.1.3 Identity 7.2 Deleting References 7.3 Mutable versus Immutable Data Types 8 Functions, Methods, and Attributes 8.1 Parameters of Functions and Methods 8.1.1 Positional Parameters 8.1.2 Keyword Arguments 8.1.3 Optional Parameters 8.1.4 Keyword-Only Parameters 8.2 Attributes 9 Sources of Information on Python 9.1 The Built-In Help Function 9.2 The Online Documentation 9.3 PEPs Part II Data Types 10 Basic Data Types: An Overview 10.1 Nothingness: NoneType 10.2 Operators 10.2.1 Operator Precedence 10.2.2 Evaluation Order 10.2.3 Concatenating Comparisons 11 Numeric Data Types 11.1 Arithmetic Operators 11.2 Comparison Operators 11.3 Conversion between Numeric Data Types 11.4 Integers: int 11.4.1 Numeral Systems 11.4.2 Bit Operations 11.4.3 Methods 11.5 Floats: float 11.5.1 Exponential Notation 11.5.2 Precision 11.5.3 Infinite and Not a Number 11.6 Boolean Values: bool 11.6.1 Logical Operators 11.6.2 Truth Values of Non-Boolean Data Types 11.6.3 Evaluating Logical Operators 11.7 Complex Numbers: complex 12 Sequential Data Types 12.1 The Difference between Text and Binary Data 12.2 Operations on Instances of Sequential Data Types 12.2.1 Checking for Elements 12.2.2 Concatenation 12.2.3 Repetition 12.2.4 Indexing 12.2.5 Slicing 12.2.6 Length of a Sequence 12.2.7 The Smallest and the Largest Element 12.2.8 Searching for an Element 12.2.9 Counting Elements 12.3 The list Data Type 12.3.1 Changing a Value within the List: Assignment via [] 12.3.2 Replacing Sublists and Inserting New Elements: Assignment via [] 12.3.3 Deleting Elements and Sublists: del in Combination with [] 12.3.4 Methods of list Instances 12.3.5 Sorting Lists: s.sort([key, reverse]) 12.3.6 Side Effects 12.3.7 List Comprehensions 12.4 Immutable Lists: tuple 12.4.1 Packing and Unpacking 12.4.2 Immutable Doesn’t Necessarily Mean Unchangeable! 12.5 Strings: str, bytes, bytearray 12.5.1 Control Characters 12.5.2 String Methods 12.5.3 Formatting Strings 12.5.4 Character Sets and Special Characters 13 Mappings and Sets 13.1 Dictionary: dict 13.1.1 Creating a Dictionary 13.1.2 Keys and Values 13.1.3 Iteration 13.1.4 Operators 13.1.5 Methods 13.1.6 Dict Comprehensions 13.2 Sets: set and frozenset 13.2.1 Creating a Set 13.2.2 Iteration 13.2.3 Operators 13.2.4 Methods 13.2.5 Mutable Sets: set 13.2.6 Immutable Sets: frozenset 14 Collections 14.1 Chained Dictionaries 14.2 Counting Frequencies 14.3 Dictionaries with Default Values 14.4 Doubly Linked Lists 14.5 Named Tuples 15 Date and Time 15.1 Elementary Time Functions—time 15.1.1 The struct_time Data Type 15.1.2 Constants 15.1.3 Functions 15.2 Object-Oriented Date Management: datetime 15.2.1 datetime.date 15.2.2 datetime.time 15.2.3 datetime.datetime 15.2.4 datetime.timedelta 15.2.5 Operations for datetime.datetime and datetime.date 15.3 Time Zones: zoneinfo 15.3.1 The IANA Time Zone Database 15.3.2 Specifying the Time in Local Time Zones 15.3.3 Calculating with Time Indications in Local Time Zones 16 Enumerations and Flags 16.1 Enumeration Types: enum 16.2 Enumeration Types for Bit Patterns: flag 16.3 Integer Enumeration Types: IntEnum Part III Advanced Programming Techniques 17 Functions 17.1 Defining a Function 17.2 Return Values 17.3 Function Objects 17.4 Optional Parameters 17.5 Keyword Arguments 17.6 Arbitrarily Many Parameters 17.7 Keyword-Only Parameters 17.8 Positional-Only Parameters 17.9 Unpacking When Calling a Function 17.10 Side Effects 17.11 Namespaces 17.11.1 Accessing Global Variables: global 17.11.2 Accessing the Global Namespace 17.11.3 Local Functions 17.11.4 Accessing Parent Namespaces: nonlocal 17.11.5 Unbound Local Variables: A Stumbling Block 17.12 Anonymous Functions 17.13 Recursion 17.14 Built-In Functions 17.14.1 abs(x) 17.14.2 all(iterable) 17.14.3 any(iterable) 17.14.4 ascii(object) 17.14.5 bin(x) 17.14.6 bool([x]) 17.14.7 bytearray([source, encoding, errors]) 17.14.8 bytes([source, encoding, errors]) 17.14.9 chr(i) 17.14.10 complex([real, imag]) 17.14.11 dict([source]) 17.14.12 divmod(a, b) 17.14.13 enumerate(iterable, [start]) 17.14.14 eval(expression, [globals, locals]) 17.14.15 exec(object, [globals, locals]) 17.14.16 filter(function, iterable) 17.14.17 float([x]) 17.14.18 format(value, [format_spec]) 17.14.19 frozenset([iterable]) 17.14.20 globals() 17.14.21 hash(object) 17.14.22 help([object]) 17.14.23 hex(x) 17.14.24 id(object) 17.14.25 input([prompt]) 17.14.26 int([x, base]) 17.14.27 len(s) 17.14.28 list([sequence]) 17.14.29 locals() 17.14.30 map(function, [*iterable]) 17.14.31 max(iterable, {default, key}), max(arg1, arg2, [*args], {key}) 17.14.32 min(iterable, {default, key}), min(arg1, arg2, [*args], {key}) 17.14.33 oct(x) 17.14.34 ord(c) 17.14.35 pow(x, y, [z]) 17.14.36 print([*objects], {sep, end, file, flush}) 17.14.37 range([start], stop, [step]) 17.14.38 repr(object) 17.14.39 reversed(sequence) 17.14.40 round(x, [n]) 17.14.41 set([iterable]) 17.14.42 sorted(iterable, [key, reverse]) 17.14.43 str([object, encoding, errors]) 17.14.44 sum(iterable, [start]) 17.14.45 tuple([iterable]) 17.14.46 type(object) 17.14.47 zip([*iterables], {strict}) 18 Modules and Packages 18.1 Importing Global Modules 18.2 Local Modules 18.2.1 Name Conflicts 18.2.2 Module-Internal References 18.2.3 Executing Modules 18.3 Packages 18.3.1 Importing All Modules of a Package 18.3.2 Namespace Packages 18.3.3 Relative Import Statements 18.4 The importlib Package 18.4.1 Importing Modules and Packages 18.4.2 Changing the Import Behavior 18.5 Planned Language Elements 19 Object-Oriented Programming 19.1 Example: A Non-Object-Oriented Account 19.1.1 Creating a New Account 19.1.2 Transferring Money 19.1.3 Depositing and Withdrawing Money 19.1.4 Viewing the Account Balance 19.2 Classes 19.2.1 Defining Methods 19.2.2 The Constructor 19.2.3 Attributes 19.2.4 Example: An Object-Oriented Account 19.3 Inheritance 19.3.1 A Simple Example 19.3.2 Overriding Methods 19.3.3 Example: Checking Account with Daily Turnover 19.3.4 Outlook 19.4 Multiple Inheritance 19.5 Property Attributes 19.5.1 Setters and Getters 19.5.2 Defining Property Attributes 19.6 Static Methods 19.7 Class Methods 19.8 Class Attributes 19.9 Built-in Functions for Object-Oriented Programming 19.9.1 Functions for Managing the Attributes of an Instance 19.9.2 Functions for Information about the Class Hierarchy 19.10 Inheriting Built-In Data Types 19.11 Magic Methods and Magic Attributes 19.11.1 General Magic Methods 19.11.2 Overloading Operators 19.11.3 Emulating Data Types: Duck Typing 19.12 Data Classes 19.12.1 Tuples and Lists 19.12.2 Dictionaries 19.12.3 Named Tuples 19.12.4 Mutable Data Classes 19.12.5 Immutable Data Classes 19.12.6 Default Values in Data Classes 20 Exception Handling 20.1 Exceptions 20.1.1 Built-In Exceptions 20.1.2 Raising an Exception 20.1.3 Handling an Exception 20.1.4 Custom Exceptions 20.1.5 Re-Raising an Exception 20.1.6 Exception Chaining 20.2 Assertions 20.3 Warnings 21 Generators and Iterators 21.1 Generators 21.1.1 Subgenerators 21.1.2 Generator Expressions 21.2 Iterators 21.2.1 The Iterator Protocol 21.2.2 Example: The Fibonacci Sequence 21.2.3 Example: The Golden Ratio 21.2.4 A Generator for the Implementation of __iter__ 21.2.5 Using Iterators 21.2.6 Multiple Iterators for the Same Instance 21.2.7 Disadvantages of Iterators Compared to Direct Access via Indexes 21.2.8 Alternative Definition for Iterable Objects 21.2.9 Function Iterators 21.3 Special Generators: itertools 21.3.1 accumulate(iterable, [func]) 21.3.2 chain([*iterables]) 21.3.3 combinations(iterable, r) 21.3.4 combinations_with_replacement(iterable, r) 21.3.5 compress(data, selectors) 21.3.6 count([start, step]) 21.3.7 cycle(iterable) 21.3.8 dropwhile(predicate, iterable) 21.3.9 filterfalse(predicate, iterable) 21.3.10 groupby(iterable, [key]) 21.3.11 islice(iterable, [start], stop, [step]) 21.3.12 permutations(iterable, [r]) 21.3.13 product([*iterables], [repeat]) 21.3.14 repeat(object, [times]) 21.3.15 starmap(function, iterable) 21.3.16 takewhile(predicate, iterable) 21.3.17 tee(iterable, [n]) 21.3.18 zip_longest([*iterables], {fillvalue}) 22 Context Manager 22.1 The with Statement 22.1.1 __enter__(self) 22.1.2 __exit__(self, exc_type, exc_value, traceback) 22.2 Helper Functions for with Contexts: contextlib 22.2.1 Dynamically Assembled Context Combinations - ExitStack 22.2.2 Suppressing Certain Exception Types 22.2.3 Redirecting the Standard Output Stream 22.2.4 Optional Contexts 22.2.5 Simple Functions as Context Manager 23 Decorators 23.1 Function Decorators 23.1.1 Decorating Functions and Methods 23.1.2 Name and Docstring after Applying a Decorator 23.1.3 Nested Decorators 23.1.4 Example: A Cache Decorator 23.2 Class Decorators 23.3 The functools Module 23.3.1 Simplifying Function Interfaces 23.3.2 Simplifying Method Interfaces 23.3.3 Caches 23.3.4 Completing Orderings of Custom Classes 23.3.5 Overloading Functions 24 Annotations for Static Type Checking 24.1 Annotations 24.1.1 Annotating Functions and Methods 24.1.2 Annotating Variables and Attributes 24.1.3 Accessing Annotations at Runtime 24.1.4 When are Annotations Evaluated? 24.2 Type Hints: The typing Module 24.2.1 Valid Type Hints 24.2.2 Container Types 24.2.3 Abstract Container Types 24.2.4 Type Aliases 24.2.5 Type Unions and Optional Values 24.2.6 Type Variables 24.3 Static Type Checking in Python: mypy 24.3.1 Installation 24.3.2 Example 25 Structural Pattern Matching 25.1 The match Statement 25.2 Pattern Types in the case Statement 25.2.1 Literal and Value Patterns 25.2.2 OR Pattern 25.2.3 Patterns with Type Checking 25.2.4 Specifying Conditions for Matches 25.2.5 Grouping Subpatterns 25.2.6 Capture and Wildcard Patterns 25.2.7 Sequence Patterns 25.2.8 Mapping Patterns 25.2.9 Patterns for Objects and Their Attribute Values Part IV The Standard Library 26 Mathematics 26.1 Mathematical Functions: math, cmath 26.1.1 General Mathematical Functions 26.1.2 Exponential and Logarithm Functions 26.1.3 Trigonometric and Hyperbolic Functions 26.1.4 Distances and Norms 26.1.5 Converting Angles 26.1.6 Representations of Complex Numbers 26.2 Random Number Generator: random 26.2.1 Saving and Loading the Random State 26.2.2 Generating Random Integers 26.2.3 Generating Random Floats 26.2.4 Random Operations on Sequences 26.2.5 SystemRandom([seed]) 26.3 Statistical Calculations: statistics 26.4 Intuitive Decimal Numbers: decimal 26.4.1 Using the Data Type 26.4.2 Nonnumeric Values 26.4.3 The Context Object 26.5 Hash Functions: hashlib 26.5.1 Using the Module 26.5.2 Other Hash Algorithms 26.5.3 Comparing Large Files 26.5.4 Passwords 27 Screen Outputs and Logging 27.1 Formatted Output of Complex Objects: pprint 27.2 Log Files: logging 27.2.1 Customizing the Message Format 27.2.2 Logging Handlers 28 Regular Expressions 28.1 Syntax of Regular Expressions 28.1.1 Any Character 28.1.2 Character Classes 28.1.3 Quantifiers 28.1.4 Predefined Character Classes 28.1.5 Other Special Characters 28.1.6 Nongreedy Quantifiers 28.1.7 Groups 28.1.8 Alternatives 28.1.9 Extensions 28.2 Using the re Module 28.2.1 Searching 28.2.2 Matching 28.2.3 Splitting a String 28.2.4 Replacing Parts of a String 28.2.5 Replacing Problem Characters 28.2.6 Compiling a Regular Expression 28.2.7 Flags 28.2.8 The Match Object 28.3 A Simple Sample Program: Searching 28.4 A More Complex Sample Program: Matching 28.5 Comments in Regular Expressions 29 Interface to Operating System and Runtime Environment 29.1 Operating System Functionality: os 29.1.1 environ 29.1.2 getpid() 29.1.3 cpu_count() 29.1.4 system(cmd) 29.1.5 popen(command, [mode, buffering]) 29.2 Accessing the Runtime Environment: sys 29.2.1 Command Line Parameters 29.2.2 Default Paths 29.2.3 Standard Input/Output Streams 29.2.4 Exiting the Program 29.2.5 Details of the Python Version 29.2.6 Operating System Details 29.2.7 Hooks 29.3 Command Line Parameters: argparse 29.3.1 Calculator: A Simple Example 29.3.2 A More Complex Example 30 File System 30.1 Accessing the File System: os 30.1.1 access(path, mode) 30.1.2 chmod(path, mode) 30.1.3 listdir([path]) 30.1.4 mkdir(path, [mode]) and makedirs(path, [mode]) 30.1.5 remove(path) 30.1.6 removedirs(path) 30.1.7 rename(src, dst) and renames(old, new) 30.1.8 walk(top, [topdown, onerror]) 30.2 File Paths: os.path 30.2.1 abspath(path) 30.2.2 basename(path) 30.2.3 commonprefix(list) 30.2.4 dirname(path) 30.2.5 join(path, *paths) 30.2.6 normcase(path) 30.2.7 split(path) 30.2.8 splitdrive(path) 30.2.9 splitext(path) 30.3 Accessing the File System: shutil 30.3.1 Directory and File Operations 30.3.2 Archive Operations 30.4 Temporary Files: tempfile 30.4.1 TemporaryFile([mode, [bufsize, suffix, prefix, dir]) 30.4.2 tempfile.TemporaryDirectory([suffix, prefix, dir]) 31 Parallel Programming 31.1 Processes, Multitasking, and Threads 31.1.1 The Lightweights among the Processes: Threads 31.1.2 Threads or Processes? 31.1.3 Cooperative Multitasking: A Third Way 31.2 Python's Interfaces for Parallelization 31.3 The Abstract Interface: concurrent.futures 31.3.1 An Example with a futures.ThreadPoolExecutor 31.3.2 Executor Instances as Context Managers 31.3.3 Using futures.ProcessPoolExecutor 31.3.4 Managing the Tasks of an Executor 31.4 The Flexible Interface: threading and multiprocessing 31.4.1 Threads in Python: threading 31.4.2 Processes in Python: multiprocessing 31.5 Cooperative Multitasking 31.5.1 Cooperative Functions: Coroutines 31.5.2 Awaitable Objects 31.5.3 The Cooperation of Coroutines: Tasks 31.5.4 A Cooperative Web Crawler 31.5.5 Blocking Operations in Coroutines 31.5.6 Other Asynchronous Language Features 31.6 Conclusion: Which Interface Is the Right One? 31.6.1 Is Cooperative Multitasking an Option? 31.6.2 Abstraction or Flexibility? 31.6.3 Threads or Processes? 32 Data Storage 32.1 XML 32.1.1 ElementTree 32.1.2 Simple API for XML 32.2 Databases 32.2.1 The Built-In Database in Python: sqlite3 32.3 Compressed Files and Archives 32.3.1 gzip.open(filename, [mode, compresslevel]) 32.3.2 Other Modules for Accessing Compressed Data 32.4 Serializing Instances: pickle 32.4.1 Functional Interface 32.4.2 Object-Oriented Interface 32.5 The JSON Data Exchange Format: json 32.6 The CSV Table Format: csv 32.6.1 Reading Data from a CSV File with reader Objects 32.6.2 Using Custom Dialects: Dialect Objects 33 Network Communication 33.1 Socket API 33.1.1 Client-Server Systems 33.1.2 UDP 33.1.3 TCP 33.1.4 Blocking and Nonblocking Sockets 33.1.5 Creating a Socket 33.1.6 The Socket Class 33.1.7 Network Byte Order 33.1.8 Multiplexing Servers: selectors 33.1.9 Object-Oriented Server Development: socketserver 33.2 XML-RPC 33.2.1 The Server 33.2.2 The Client 33.2.3 Multicall 33.2.4 Limitations 34 Accessing Resources on the Internet 34.1 Protocols 34.1.1 Hypertext Transfer Protocol 34.1.2 File Transfer Protocol 34.2 Solutions 34.2.1 Outdated Solutions for Python 2 34.2.2 Solutions in the Standard Library 34.2.3 Third-Party Solutions 34.3 The Easy Way: requests 34.3.1 Simple Requests via GET and POST 34.3.2 Web APIs 34.4 URLs: urllib 34.4.1 Accessing Remote Resources: urllib.request 34.4.2 Reading and Processing URLs: urllib.parse 34.5 FTP: ftplib 34.5.1 Connecting to an FTP Server 34.5.2 Executing FTP commands 34.5.3 Working with Files and Directories 34.5.4 Transferring Files 35 Email 35.1 SMTP: smtplib 35.1.1 SMTP([host, port, local_hostname, timeout, source_address]) 35.1.2 Establishing and Terminating a Connection 35.1.3 Sending an Email 35.1.4 Example 35.2 POP3: poplib 35.2.1 POP3(host, [port, timeout]) 35.2.2 Establishing and Terminating a Connection 35.2.3 Listing Existing Emails 35.2.4 Retrieving and Deleting Emails 35.2.5 Example 35.3 IMAP4: imaplib 35.3.1 IMAP4([host, port, timeout]) 35.3.2 Establishing and Terminating a Connection 35.3.3 Finding and Selecting a Mailbox 35.3.4 Operations with Mailboxes 35.3.5 Searching Emails 35.3.6 Retrieving Emails 35.3.7 Example 35.4 Creating Complex Emails: email 35.4.1 Creating a Simple Email 35.4.2 Creating an Email with Attachments 35.4.3 Reading an Email 36 Debugging and Quality Assurance 36.1 The Debugger 36.2 Automated Testing 36.2.1 Test Cases in Docstrings: doctest 36.2.2 Unit Tests: unittest 36.3 Analyzing the Runtime Performance 36.3.1 Runtime Measurement: timeit 36.3.2 Profiling: cProfile 36.3.3 Tracing: trace 37 Documentation 37.1 Docstrings 37.2 Automatically Generated Documentation: pydoc Part V Advanced Topics 38 Distributing Python Projects 38.1 A History of Distributions in Python 38.1.1 The Classic Approach: distutils 38.1.2 The New Standard: setuptools 38.1.3 The Package Index: PyPI 38.2 Creating Distributions: setuptools 38.2.1 Installation 38.2.2 Writing the Module 38.2.3 The Installation Script 38.2.4 Creating a Source Distribution 38.2.5 Creating a Binary Distribution 38.2.6 Installing Distributions 38.3 Creating EXE files: cx_Freeze 38.3.1 Installation 38.3.2 Usage 38.4 Package Manager 38.4.1 The Python Package Manager: pip 38.4.2 The conda Package Manager 38.5 Localizing Programs: gettext 38.5.1 Example of Using gettext 38.5.2 Creating the Language Compilation 39 Virtual Environments 39.1 Using Virtual Environments: venv 39.1.1 Activating a Virtual Environment 39.1.2 Working in a Virtual Environment 39.1.3 Deactivating a Virtual Environment 39.2 Virtual Environments in Anaconda 40 Alternative Interpreters and Compilers 40.1 Just-in-Time Compilation: PyPy 40.1.1 Installation and Use 40.1.2 Example 40.2 Numba 40.2.1 Installation 40.2.2 Example 40.3 Connecting to C and C++: Cython 40.3.1 Installation 40.3.2 The Functionality of Cython 40.3.3 Compiling a Cython Program 40.3.4 A Cython Program with Static Typing 40.3.5 Using a C Library 40.4 The Interactive Python Shell: IPython 40.4.1 Installation 40.4.2 The Interactive Shell 40.4.3 The Jupyter Notebook 41 Graphical User Interfaces 41.1 Toolkits 41.1.1 Tkinter (Tk) 41.1.2 PyGObject (GTK) 41.1.3 Qt for Python (Qt) 41.1.4 wxPython (wxWidgets) 41.2 Introduction to tkinter 41.2.1 A Simple Example 41.2.2 Control Variables 41.2.3 The Packer 41.2.4 Events 41.2.5 Widgets 41.2.6 Drawings: The Canvas Widget 41.2.7 Other Modules 41.3 Introduction to PySide6 41.3.1 Installation 41.3.2 Basic Concepts of Qt 41.3.3 Development Process 41.4 Signals and Slots 41.5 Important Widgets 41.5.1 QCheckBox 41.5.2 QComboBox 41.5.3 QDateEdit, QTimeEdit, and QDateTimeEdit 41.5.4 QDialog 41.5.5 QLineEdit 41.5.6 QListWidget and QListView 41.5.7 QProgressBar 41.5.8 QPushButton 41.5.9 QRadioButton 41.5.10 QSlider and QDial 41.5.11 QTextEdit 41.5.12 QWidget 41.6 Drawing Functionality 41.6.1 Tools 41.6.2 Coordinate System 41.6.3 Simple Shapes 41.6.4 Images 41.6.5 Text 41.6.6 Eye Candy 41.7 Model-View Architecture 41.7.1 Sample Project: An Address Book 41.7.2 Selecting Entries 41.7.3 Editing Entries 42 Python as a Server-Side Programming Language on the Web: An Introduction to Django 42.1 Concepts and Features of Django 42.2 Installing Django 42.3 Creating a New Django Project 42.3.1 The Development Web Server 42.3.2 Configuring the Project 42.4 Creating an Application 42.4.1 Importing the Application into the Project 42.4.2 Defining a Model 42.4.3 Relationships between Models 42.4.4 Transferring the Model to the Database 42.4.5 The Model API 42.4.6 The Project Gets a Face 42.4.7 Django's Template System 42.4.8 Processing Form Data 42.4.9 Django’s Admin Control Panel 43 Scientific Computing and Data Science 43.1 Installation 43.2 The Model Program 43.2.1 Importing numpy, scipy, and matplotlib 43.2.2 Vectorization and the numpy.ndarray Data Type 43.2.3 Visualizing Data Using matplotlib.pyplot 43.3 Overview of the numpy and scipy Modules 43.3.1 Overview of the numpy.ndarray Data Type 43.3.2 Overview of scipy 43.4 An Introduction to Data Analysis with pandas 43.4.1 The DataFrame Object 43.4.2 Selective Data Access 43.4.3 Deleting Rows and Columns 43.4.4 Inserting Rows and Columns 43.4.5 Logical Expressions on Data Records 43.4.6 Manipulating Data Records 43.4.7 Input and Output 43.4.8 Visualization 44 Inside Knowledge 44.1 Opening URLs in the Default Browser: webbrowser 44.2 Interpreting Binary Data: struct 44.3 Hidden Password Entry 44.3.1 getpass([prompt, stream]) 44.3.2 getpass.getuser() 44.4 Command Line Interpreter 44.5 File Interface for Strings: io.StringIO 44.6 Generators as Consumers 44.6.1 A Decorator for Consuming Generator Functions 44.6.2 Triggering Exceptions in a Generator 44.6.3 A Pipeline as a Chain of Consuming Generator Functions 44.7 Copying Instances: copy 44.8 Image Processing: Pillow 44.8.1 Installation 44.8.2 Loading and Saving Image Files 44.8.3 Accessing Individual Pixels 44.8.4 Manipulating Images 44.8.5 Interoperability 45 From Python 2 to Python 3 45.1 The Main Differences 45.1.1 Input/Output 45.1.2 Iterators 45.1.3 Strings 45.1.4 Integers 45.1.5 Exception Handling 45.1.6 Standard Library 45.2 Automatic Conversion A Appendix A.1 Reserved Words A.2 Operator Precedence A.3 Built-In Functions A.4 Built-In Exceptions A.5 Python IDEs A.5.1 PyCharm A.5.2 Visual Studio Code A.5.3 PyDev A.5.4 Spyder B The Authors Index Service Pages Legal Notes