class A:
    cache = []

    def __init__(self, items=None):
        if items is None:
            items = []
        self.items = items
        self.cache.append(len(self.items))


x = A([1, 2])
y = A()
z = A()

x.items.append(3)
y.items.extend([10, 20])

print(x.items, y.items, z.items, A.cache)

pip install fastapi uvicorn

from fastapi import FastAPI

app = FastAPI()

@app.get("/hello")
async def hello(name: str = "Python"):
    return {"msg": f"Hello {name}!"}

# اجرا:
# uvicorn main:app --reload

funcs = []

for i in range(3):
    funcs.append(lambda x, p=i: x * p)

result = sum(f(10) for f in funcs)
print(result)

def append_item(item, data=[]):
    data.append(item)
    return data

x = append_item(1)
y = append_item(2)

z = append_item(3, data=[])
w = append_item(4)

print(x)
print(y)
print(z)
print(w)

def is_valid_user(data: dict) -> bool:
    required_keys = ["username", "email", "password"]

    # همه فیلدها باید وجود داشته باشند و خالی نباشند
    return all(
        key in data and isinstance(data[key], str) and data[key].strip()
        for key in required_keys
    )

user = {"username": "ali", "email": "", "password": "123"}
print(is_valid_user(user))  # False

pip install django

django-admin startproject mysite
cd mysite
python manage.py startapp blog
python manage.py runserver

data = [3, 1, 2, 1]

calls = []

def key_fn(x):
    calls.append(x)
    return 0

result = sorted(data, key=key_fn)

print("calls:", calls)
print("result:", result)

pip install pandas

import pandas as pd

# خواندن فایل CSV
df = pd.read_csv("data.csv")

# انتخاب سطرهایی که مقدار ستون "age" >= 18 است
adults = df[df["age"] >= 18]

# میانگین سن
mean_age = adults["age"].mean()
print(mean_age)