南栀 Space

1
mood_index = int(input("Enter mood index: "))
2
if mood_index >= 60:
3
    print("congratulation!")
4
elif 30 <mood_index < 60:
5
    print("Nromal.")
6
else:
7
    print("Sorry.")

1
a = [0,1,2,3,4]
2

3
print(a[::-1])

1
[4,3,2,1,0]

1
shopping_list = ["apple", "banana", "cherry"]
2
shopping_list.append("orange")
3
print(shopping_list[0])
4

5
price = [100,200,301,129]
6
max_price = max(price)
7
min_price = min(price)
8
sorted_price = sorted(price)
9
print(max_price)
10
print(min_price)
11
print(sorted_price)

1
a = [1, 2, 3]
2
a.insert(1, 100)
3
print(a)    # [1, 100, 2, 3]

1
a = [1, 2, 3]
2
x = a.pop(1)
3
print(x)    # 2
4
print(a)    # [1, 3]

1
lst = ['a', 'b', 'c']
2

3
for i, v in enumerate(lst):
4
    print(i, v)

1
0 a
2
1 b
3
2 c

1
print(len(t))
2
for i in range(len(t)):
3
    print(i,t[i])

1
contacts = {
2
    ("xioamin",23):"111111111",
3
    ("xiaohua",24):"222222222"
4
}
5
del contacts[("xioamin",23)]
6
contacts[("xiaomei",24)] = "123131"
7
print(contacts)
8
print(len(contacts))

1
student_grades = {
2
    "语文": 90,
3
    "数学": 95,
4
    "英语": 88,
5
    "科学": 92
6
}
7
# 访问 '数学' 键对应的值
8
math_score = student_grades["数学"]
9
print(math_score)  # 输出: 95

1
2. 使用`.get(key, default=None)` 方法  （`default`为键不存在时返回的默认值）

1
for k, v in d.items():
2
    print(k, v)

1
match data:
2
    case pattern1:
3
        ...
4
    case pattern2:
5
        ...

1
match data:
2
    case {}:
3
        print("空字典")
4
    case []:
5
        print("空列表")
6
    case ():
7
        print("空元组")
8
    case _:
9
        print("其他情况")

1
match data1, data2:
2
    case 1, 2:
3
        print("data1=1, data2=2")

1
try:
2
    xxx() #自定义函数
3

4
except Exception as e:  #不写默认为Exception
5
    print("输入错误")
6
    raise #层层向上报错

1
BaseException
2
 ├── SystemExit
3
 ├── KeyboardInterrupt
4
 └── Exception
5
       ├── TypeError #类型不对
6
       ├── ValueError #值不合法
7
       ├── IndexError #下标越界
8
       ├── KeyError #字典没这个键
9
       └── FileNotFoundError #文件不存在

1
try:
2
    x = int(input())
3
except (ValueError, TypeError):
4
    print("输入不合法")

1
try:
2
    代码
3
except 异常类型:
4
    处理
5
else:
6
    没有异常执行
7
finally:
8
    一定执行

1
import copy
2

3
lst1 = [1, 2, [3, 4]]
4

5
lst2 = lst1.copy()        # 方法一
6
lst3 = lst1[:]            # 方法二
7
lst4 = copy.copy(lst1)    # 方法三

1
import copy
2

3
lst1 = [1, 2, [3, 4]]
4
lst2 = copy.deepcopy(lst1)

1
nums= [1,2,3,4,5,6]
2
my_list = [i for i in nums]

1
def f(a, b):
2
    ...

1
def greet(name="Nanzhi"):
2
    print("Hello", name)

1
x = lambda a : a + 10
2
print(x(5))

1
def sum_all(*nums):
2
    print(nums)

1
def info(**data):
2
    print(data)

1
lambda 参数1, 参数2, ...: 表达式

1
f = lambda x: x + 1
2
print(f(5))  # 6

1
x = 10  # 全局变量
2

3
def foo():
4
    y = 5  # 局部变量

1
def foo():
2
    global x
3
    x = 20

1
def hello():
2
    print("Hi")
3

4
f = hello
5
f()   # 等价于 hello()

1
class Student:
2
    school = "xxx_university" #类属性
3

4
    def __init__(self,name):
5
        self.name = name #实例属性

1
a.gender = '男'  #动态添加属性
2
print(f"我是{a.gender}生")

1
    def show(self,age):
2
        self.age = age
3
        print(f"我今年{se  lf.age}岁了")
4

5
a=Student("xiaomin")
6
a.show(18)

1
class Person:
2
    @staticmethod
3
    def test():
4
        print("静态方法不能使用实例属性和实例方法")

1
class MyClass:
2
    @classmethod
3
    def my_class_method(cls):
4
        print(cls)

1
a.func=introduce #函数的一个赋值
2
#func是a对象的方法
3
a.func() #调用

1
stu=Student('nz',18) #创建对象
2
print(stu.name,stu.age) #调用实例属性
3
print(Student.school) #调用类属性
4
stu.show() #调用实例方法
5
Student.sm() #调用静态方法
6
Student.cm() #调用类方法

1
class Student():
2
    def __init__(self,name,age,gender):
3
        self._name = name #self_name受保护，只能本类和子类访问
4
        self.__age = age #self.__age表示私有的，只能类本身去访问
5
        self.gender = gender #普通的实例属性
6

7
    def _func1(self): #受保护的
8
        print("子类及本身可以访问")
9

10
    def __func2(self): #私有的
11
        print("只有定义的类可以访问")
12

13
    def show(self): #普通的实例方法
14
        self._func1() #类本身访问受保护的方法
15
        self.__func2() #类本身访问私有方法
16
        print(self._name) #受保护的实例属性
17
        print(self.__age) #私有实例属性
18

19
stu=Student("xiaomin",18,"男")
20
stu.show()

1
class Person:
2
    def __init__(self):
3
        self.__age = 18
4

5
    def __secret(self):
6
        print("这是秘密")
7

8
    def get_age(self):
9
        return self.__age

1
p = Person()
2
print(p.get_age())

1
__attr  →  _类名__attr

1
class Person:
2
    def __init__(self, age):
3
        self._age = age   # 内部属性
4

5
    @property
6
    def age(self):
7
        return self._age

1
p = Person(18)
2
print(p.age)   # 看起来是属性
3
#实际上执行 Person.age(p)

1
class Person:
2
    def __init__(self, age):
3
        self._age = age
4

5
    @property
6
    def age(self):
7
        return self._age
8

9
    @age.setter #属性名.setter
10
    def age(self, value):
11
        if value < 0:
12
            raise ValueError("age must be non-negative")
13
        self._age = value

1
p.age = 20   # 自动调用 setter

1
class Person:
2
    def __init__(self,name,age):
3
        self.name = name
4
        self.age = age
5
    def show(self):
6
        print(f"大家好，这里是{self.name},今年{self.age}")
7

8
#Student继承Person类
9
class Student(Person):
10
    def __init__(self,name,age,id):
11
        super().__init__(name,age) #调用父类的初始化方法
12
        self.id = id
13

14
#Doctor继承Person类
15
class Doctor(Person):
16
    def __init__(self, name, age,department):
17
        super().__init__(name, age)
18
        self.department = department
19

20
#创建一个子类对象
21
stu=Student("xiaomin",18,"1001")
22
stu.show()
23

24
doctor=Doctor("zhangsan",30,"内科")
25
doctor.show()

1
class FatherA():
2
    def __init__(self,name):
3
        self.name = name
4

5
    def showA(self):
6
        print(f"我是父类A中的方法")
7

8
class FatherB():
9
    def __init__(self,age):
10
        self.age = age
11

12
    def showB(self):
13
        print(f"我是父类B中的方法")
14

15
#多继承
16
class Son(FatherA,FatherB):
17
    def __init__(self,name,age,id):
18
        FatherA.__init__(self,name) #调用父类A的初始化方法
19
        FatherB.__init__(self,age)  #调用父类B的初始化方法
20
        self.id = id
21

22
son=Son("xiaoming",18,"1001")
23
son.showA()
24
son.showB()

1
class Person:
2
    def __init__(self,name,age):
3
        self.name = name
4
        self.age = age
5
    def show(self):
6
        print(f"大家好，这里是{self.name},今年{self.age}")
7

8
#Student继承Person类
9
class Student(Person):
10
    def __init__(self,name,age,id):
11
        super().__init__(name,age) #调用父类的初始化方法
12
        self.id = id
13

14
    def show(self):
15
        super().show() #调用父类中的方法
16
        print(f"我的学号是{self.id}")
17

18

19
#Doctor继承Person类
20
class Doctor(Person):
21
    def __init__(self, name, age,department):
22
        super().__init__(name, age)
23
        self.department = department
24

25
#创建一个子类对象
26
stu=Student("xiaomin",18,"1001")
27
stu.show()
28

29
doctor=Doctor("zhangsan",30,"内科")
30
doctor.show()

1
class Person:
2
    def __init__(self, name, age):
3
        self.name = name    # 给对象绑定属性
4
        self.age = age
5

6
p = Person("Tom", 20)   # 自动调用 __init__

1
class CuteCat:
2
    def __init__(self,cat_name,cat_age,cat_color):
3
        self.name = cat_name
4
        self.age = cat_age
5

6
cat1 = CuteCat("jojo", 12,"orange")
7
print(f"{cat1.name} is {cat1.age} years old")

1
self.name = name

1
self.score = 0

1
class Test:
2
    def __init__(self):
3
        print("构造函数被调用了")
4

5
t = Test()

1
class MyOpen:
2
    def __init__(self,filepath):
3
        print("Entering constructor of MyOpen")
4
        self.filepath = filepath
5

6
    def __enter__(self):
7
        print("Ent  ering __enter__ of MyOpen")
8
        return self.filepath
9

10
    def __exit__(self,exc_type,exc_value,traceback):
11
        print("Entering __exit__ of MyOpen")
12

13
with MyOpen('data.txt') as file:
14
    print(f"the value of file is {file}")

1
f = open("./data.txt","r",encoding="utf-8")
2
print(f.read()) #内括号可以写入读取的字节数

1
f = open("./data.txt","r",encoding="utf-8")
2
lines = f.readlines()
3
for line in lines:
4
    print(line)
5
f.close() #关闭文件，释放资源

1
# data.txt 在 with 块结束后，无论是否发生错误，都会自动调用 file.close() 方法
2
with open('data.txt', 'r', encoding='utf-8') as file:
3
    content = file.read()
4
    print(content)
5

6
# 在 with 块外部，文件已经被安全关闭

1
with open('output.txt', 'w', encoding='utf-8') as f:
2
    # 写入第一行，必须手动添加换行符
3
    f.write("这是写入文件的第一行。\n")
4

5
    # 写入第二行
6
    f.write("这是第二行内容。\n")

1
# 'r+': 读写模式，指针在开头
2
with open("./data.txt", "r+", encoding="utf-8") as f:
3
    f.write("hello!\n") # 写入，指针移动到写入内容的末尾
4
    f.write("yoo")     # 继续写入，指针移动到新的末尾
5

6
    # --- 关键步骤 ---
7
    # 将文件指针移回文件开头 (位置 0)
8
    f.seek(0)
9

10
    # 重新读取整个文件的内容
11
    print(f.read())

1
numbers = [1,2,3,4,5]
2
first,*rest = numbers
3
print(first)
4
print(rest)

1
1
2
[2, 3, 4, 5]

1
def print_values(*args):
2
    for arg in args:
3
        print(arg)
4

5
print_values(1,2,3,4)

1
list1 =[1,2,3]
2
tuple1 = (4,5,6)
3
merged = [*list1,*tuple1]
4
print(merged)
5
# [1, 2, 3, 4, 5, 6]

1
def greet(name,age):
2
    print(f"hello{name},you are {age} years old")
3

4
person =('Alice',30)
5
greet(*person)

1
def example(**kwargs):
2
    for key,value in kwargs.items():
3
        print(f"{key}={value}")
4

5
example(a=1,b=2)

1
def create_profile(name,age,email):
2
    print(f"name : {name}")
3
    print(f"age : {age}")
4
    print(f"email : {email}")
5

6
option = {
7
    "name":"tony",
8
    "age":18,
9
    "email":"tony@qq.com"
10
}
11

12
create_profile(**option)

1
# 工厂模式
2
class DatabaseConnection:
3
    def __init__(self,host,port,username,password):
4
        self.host = host
5
        self.port = port
6
        self.username = username
7
        self.password = password
8

9
    def connect(self):
10
        return f'Connecting to database at {self.host}:{self.port} with username {self.username}'
11

12
def connection_factory(db_type):
13
    db_config ={
14
            'main':{
15
                'host': 'localhost',
16
                'port': 3306,
17
                'username': 'root',
18
                'password':'password123'
19
            },
20
            'analytics':{
21
                'host': '192.168.1.1',
22
                'port': 5432,
23
                'username': 'admin',
24
                'password':'pass3'
25
            },
26
            'cache':{
27
                'host': '10.0.0.1',
28
                'port': 27017,
29
                'username': 'cacher',
30
                'password':'cipher'
31
            }
32
     }
33
    return DatabaseConnection(**db_config[db_type]) #字典解包
34

35

36
def client():
37
    main_db = connection_factory('main')
38
    analytics_db = connection_factory('analytics')
39
    cache_db = connection_factory('cache')
40

41
    print(main_db.connect())
42
    print(analytics_db.connect())
43
    print(cache_db.connect())
44

45
client()

1
class DatabaseConnection:
2
    _instance = None
3

4
    def __new__(cls,*args,**kwargs) -> Self:
5
        if cls._instance is None:
6
            cls._instance = super().__new__(cls)
7
        return cls._instance

1
project/
2
  main.py
3
  moduleA.py

1
def hello():
2
    print("Hello from module!")

1
import moduleA
2

3
mytool.hello()

1
my_package/
2
    __init__.py
3
    util.py

1
import my_package

1
def generator(n):
2
    for i in range(n):
3
        print('before yield')
4
        yield i
5
        print("after yield")
6

7
gen = generator(3) #gen 为生成器
8
print(next(gen)) #生成0后退             出生成器函数
9
print("---")
10
for i in gen:
11
    print(i)

1
before yield
2
0
3
---
4
after yield
5
before yield
6
1
7
after yield
8
before yield
9
2
10
after yield