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https://blog.codejourney.top/A technical blog by Antvictor featuring tutorials on Java, Python, and software design principles. Content includes a 'Seven Day Python' introductory series, guides on Nacos integration with SpringBoot and SpringCloud, and explanations of design principles such as the Open-Closed Principle (OCP), Liskov Substitution Principle, and Single Responsibility Principle.
The Single Responsibility Principle (SRP) states that a class should have one, and only one, reason to change. This means a class should be responsible for only one type of functionality.
When a class has too many responsibilities, changes to one responsibility may inadvertently introduce bugs or errors into others. It is important to note that SRP does not mean a class can only perform one single action, but rather that it should perform actions of the same type or category (e.g., a Chef class handles various cooking tasks, but should not handle order taking or payment).
class is a blueprint used to define a new type by abstracting common characteristics and behaviors of a group of entities. An object is a concrete instance of a class that exists in memory and possesses state, identity, and behavior. While the class defines the structure, the object is the actual entity created by the developer during runtime.The Liskov Substitution Principle (LSP) is a fundamental principle of object-oriented design used to constrain inheritance. It states that if for every object o1, there exists an object o2 such that replacing o1 with o2 does not change the program's behavior, then o2 is a subtype of o1.
In practical terms: a parent class should be replaceable by its child class without affecting the business logic or correctness of the application. If a subclass cannot fully implement the business logic of the parent class, inheritance should be avoided in favor of dependency, aggregation, or composition.
The Liskov Substitution Principle (LSP) is a fundamental principle of object-oriented design that constrains the use of inheritance. It states that if for every object o1, there exists an object o2 such that replacing o1 with o2 does not change the program's behavior, then o2 is a subtype of o1.
In practical terms: a derived class must be substitutable for its base class without affecting the correctness or business logic of the application. If a subclass cannot fully implement the business logic of the parent class, inheritance should be avoided in favor of dependency, aggregation, or composition.
__). Private members can still be called by other methods within the same class.class Penguin(Bird):
def __cry(self):
print("I only bark at home") # Private method
def cry(self):
print("This is my public cry")
self.__cry() # Internal call is allowed
p = Penguin("small wings", "villus")
p.cry() # Works
# p.__cry() # Raises AttributeErrorDownload the installation package (version 3.6 or higher) from the official Python website (python.org).
python3.python in the command prompt (cmd).# macOS verification
python3
# Windows verification
pythonbreak to terminate a loop entirely when a specific condition is met. Use continue to skip the remainder of the current iteration and jump immediately to the next cycle of the loop.boxes = [1, 2, 3, 4, 5, 6]
# Example of break: stops loop when i is 3
for i in boxes:
if i == 3:
break
print(i) # Prints 1, 2
# Example of continue: skips 3 and continues with 4
for i in boxes:
if i == 3:
continue
print(i) # Prints 1, 2, 4, 5, 6# Option 1: Install from source
git clone https://github.com/alibaba/nacos.git
cd nacos/
mvn -Prelease-nacos -Dmaven.test.skip=true clean install -U
cd distribution/target/nacos-server-$version/nacos/bin
# Option 2: Install from binary (Recommended)
unzip nacos-server-$version.zip # or tar -xvf nacos-server-$version.tar.gz
cd nacos/binTo install and run Nacos, the following environment prerequisites must be met:
# say.py
def say(name):
print(f"hello, {name}")
def say1(name):
print(f"Hi, {name}")
# call.py
# Option 1: Direct import
import say
say.say("AntVictor")
# Option 2: Import with alias
import say as s
s.say("AntVictor")
# Option 3: Import specific functions
from say import say, say1
say("AntVictor")
say1("AntVictor")