The Best Object-Oriented Programming Tutorials for Beginners on the Net: 49 Python Functions Methods and Interfaces - Difference Between Functions and Methods and lamda Anonymous Functions
Abstracts:
In Python, functions and methods are both basic units of code, used to encapsulate and perform specific tasks; there are some important differences between them, and lambda anonymous functions are a way Python provides to succinctly define small functions.
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FreakStudio's Blog
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You're learning embedded and you don't know how to be object oriented?
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 00 Introduction to Object-Oriented Design Methods
The network's most suitable for the introduction of object-oriented programming tutorials: 01 Basic Concepts of Object-Oriented Programming
The Best Object-Oriented Programming Tutorials for Getting Started on the Web: 02 Python Implementations of Classes and Objects - Creating Classes with Python
The Best Object-Oriented Programming Tutorials for Getting Started on the Web: 03 Python Implementations of Classes and Objects - Adding Attributes to Custom Classes
The Best Object-Oriented Programming Tutorial on the Net for Getting Started: 04 Python Implementation of Classes and Objects - Adding Methods to Custom Classes
The Best Object-Oriented Programming Tutorial on the Net for Getting Started: 05 Python Implementation of Classes and Objects - PyCharm Code Tags
The best object-oriented programming tutorials on the net for getting started: 06 Python implementation of classes and objects - data encapsulation of custom classes
The best object-oriented programming tutorial on the net for getting started: 07 Python implementation of classes and objects - type annotations
The best object-oriented programming tutorials on the net for getting started: 08 Python implementations of classes and objects - @property decorator
The best object-oriented programming tutorials on the net for getting started: 09 Python implementation of classes and objects - the relationship between classes
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 10 Python Implementations of Classes and Objects - Class Inheritance and Richter's Replacement Principle
The best object-oriented programming tutorials on the net for getting started: 11 Python implementation of classes and objects - subclasses call parent class methods
The network's most suitable for the introduction of object-oriented programming tutorials: 12 classes and objects of the Python implementation - Python using the logging module to output the program running logs
The network's most suitable for the introduction of object-oriented programming tutorials: 13 classes and objects of the Python implementation - visual reading code artifacts Sourcetrail's installation use
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 14 Python Implementations of Classes and Objects - Static Methods and Class Methods for Classes
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 15 Python Implementations of Classes and Objects - __slots__ Magic Methods
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 16 Python Implementations of Classes and Objects - Polymorphism, Method Overriding, and the Principle of Open-Close
The Best Object-Oriented Programming Tutorials for Getting Started on the Web: 17 Python Implementations of Classes and Objects - Duck Types and "file-like objects"
The network's most suitable for the introduction of object-oriented programming tutorials: 18 classes and objects Python implementation - multiple inheritance and PyQtGraph serial data plotting graphs
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 19 Python Implementations of Classes and Objects - Using PyCharm to Automatically Generate File Annotations and Function Annotations
The best object-oriented programming tutorials on the web for getting started: 20 Python implementation of classes and objects - Combinatorial relationship implementation and CSV file saving
The best introductory object-oriented programming tutorials on the net: 21 Python implementation of classes and objects - Organization of multiple files: modulemodule and packagepackage
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 22 Python Implementations of Classes and Objects - Exceptions and Syntax Errors
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 23 Python Implementation of Classes and Objects - Throwing Exceptions
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 24 Python Implementations of Classes and Objects - Exception Catching and Handling
The best object-oriented programming tutorials on the web for getting started: 25 Python implementation of classes and objects - Python to determine the type of input data
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 26 Python Implementations of Classes and Objects - Context Managers and with Statements
The best introductory object-oriented programming tutorials on the web: 27 Python implementation of classes and objects - Exception hierarchy and custom exception class implementation in Python
The best object-oriented programming tutorials on the net for getting started: 28 Python implementations of classes and objects - Python programming principles, philosophies and norms in a big summary
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 29 Python Implementations of Classes and Objects - Assertions and Defensive Programming and Use of the help Function
The Best Object-Oriented Programming Tutorials for Getting Started on the Web: 30 Python's Built-In Data Types - the root class of object
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 31 Python's Built-In Data Types - Object Object and Type Type
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 32 Python's Built-in Data Types - Class Class and Instance Instance
The Best Object-Oriented Programming Tutorials for Getting Started on the Web: 33 Python's Built-In Data Types - The Relationship Between the Object Object and the Type Type
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 34 Python's Built-In Data Types - Python's Common Compound Data Types: Tuples and Named Tuples
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 35 Python's Built-In Data Types - Document Strings and the __doc__ Attribute
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 36 Python's Built-In Data Types - Dictionaries
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 37 Python's Common Composite Data Types - Lists and List Derivatives
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 38 Python's Common Composite Data Types - Using Lists to Implement Stacks, Queues, and Double-Ended Queues
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 39 Python Common Composite Data Types - Collections
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 40 Python's Common Compound Data Types - Enumeration and Use of the enum Module
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 41 Python's Common Composite Data Types - Queues (FIFO, LIFO, Priority Queue, Double-Ended Queue, and Ring Queue)
The best introductory object-oriented programming tutorials on the web: 42 Python commonly used composite data types-collections container data type
The Best Object-Oriented Programming Tutorials on the Web for Getting Started: 43 Python's Common Composite Data Types - Extended Built-In Data Types
The Best Object-Oriented Programming Tutorial on the Net for Getting Started: 44 Python Built-In Functions and Magic Methods - Magic Methods for Rewriting Built-In Types
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 45 Python Implementations of Common Data Structures - Chain Tables, Trees, Hash Tables, Graphs, and Heaps
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 46 Python Function Methods and Interfaces - Functions and Event-Driven Frameworks
The network's most suitable for the introduction of object-oriented programming tutorials: 47 Python function methods and interfaces - callback function Callback
The Best Object-Oriented Programming Tutorials on the Net for Getting Started: 48 Python Function Methods and Interfaces - Positional Arguments, Default Arguments, Variable Arguments, and Keyword Arguments
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Documentation and code acquisition:
The following link can be accessed to download the document:
/leezisheng/Doc
This document mainly introduces how to use Python for object-oriented programming, which requires readers to have a basic understanding of Python syntax and microcontroller development. Compared with other blogs or books that explain Python object-oriented programming, this document is more detailed and focuses on embedded host computer applications, with common serial port data sending and receiving, data processing, and dynamic graph drawing as application examples for the host computer and the lower computer, and using Sourcetrail code software to visualize and read the code for readers' easy understanding.
The link to get the relevant sample code is below:/leezisheng/Python-OOP-Demo
main body (of a book)
Functions and methods
Function is encapsulated in some independent functions, can be called directly, can pass some data (parameters) into the processing, and then return some data (return value), can also have no return value. Can be defined directly in the module to use. All the data passed to the function are passed explicitly.
Methods are similar to functions in that they also encapsulate independent functionality, but methods are invoked only in dependence on the class or object and represent targeted operations. The data self and cls are implicitly passed to the method, i.e. the caller of the method, and the method can manipulate data inside the class. In short, functions exist independently in python and can be used directly, whereas methods must be called by someone else in order to be realized.
In short, functions that are not bound to classes and instances are functions; functions that are bound to classes and instances are methods.
In fact, the method of the class does not necessarily have to be implemented in the class, but also in the class first declaration without specific implementation, in the class outside the implementation and assignment of value to the attribute (implementation of specific methods). The example code is as follows:
_# Define the Cat class _#
class Cat.
def say(self).
print("I' m a cat")
cat1 = Cat()
_# Define the lie method _
lie = lambda self: print("I' m a dog")
_# Add lie method _
= lie
_# View Cat class attributes _
print(dir(Cat))
()
The following is the result, you can see that the lie method has been successfully added to the Cat class.
lamda function/anonymous function
A lambda function is a small, anonymous, inline function that can take any number of arguments, but can only have one expression. Anonymous functions do not require the def keyword to define the full function. lambda functions are typically used to write simple, one-line functions, often in situations where a function needs to be passed as a parameter, such as in map(), filter(), reduce(), and so on.
lambda syntax format:
lambda arguments: expression
Parameters of a lambda expression.
- lambda is Python's keyword for defining lambda functions
- arguments is a list of arguments, which can contain zero or more arguments, but must be specified before a colon (:).
- expression is an expression that calculates and returns the result of a function.
The following example uses lambda to create an anonymous function that multiplies a and b and returns the result:
x = lambda a, b : a * b
print(x(5, 6))
The lambda function can also be used with built-in functions such as map(), filter(), and reduce() to perform operations on collections.
For example, with the map() function to implement a list of squaring operations, map() function is the prototype of map (function, iterable, ......), which results in the return of a list, the meaning of this function is to apply function to each of the iterable's element of iterable, and the result is returned as a list.
numbers = [1, 2, 3, 4, 5]
squared = list(map(lambda x: x**2, numbers))
print(squared)
or with the filter function to filter elements in a list. filter() function can filter certain elements from an iterable object (such as a dictionary, list) and generate a new iterator. filter(function, iterable) function returns an iterable filter object, which can be transformed into a list using the list() function. which can be transformed into a list containing all the items returned in the filter object. In the following example, we have filtered out an even number of items from the list:
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers)
Or with the reduce() function, reduce() function will accumulate the elements in the parameter sequence. reduce(function, iterable[, initializer]) will be a collection of data (chained lists, tuples, etc.) in all the data to perform the following operations: with the function function passed to the reduce in the function (with two arguments) to reduce the first two elements of the collection, the result of the third data with the function function operation, and finally get a result.
from functools import reduce
numbers = [1, 2, 3, 4, 5]
_# utilization reduce() cap (a poem) lambda The function calculates the product_
product = reduce(lambda x, y: x * y, numbers)
print(product)
