words = ["Python", "очень", "крут"]
result = ""
for w in words:
    result += w + " "
print(result)

words = ["Python", "очень", "крут"]
result = " ".join(words)
print(result)

lines = ["строка 1", "строка 2", "строка 3"]
text = "\n".join(lines)
print(text)

строка 1
строка 2
строка 3

import json

data = '{"name": "Alice", "age": 25}'
parsed = json.loads(data)
print(parsed["name"])  # Alice

from bs4 import BeautifulSoup

html = "<h1>Hello <b>Python</b></h1>"
soup = BeautifulSoup(html, "html.parser")
print(soup.h1.text)  # Hello Python

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("--name")
args = parser.parse_args()
print(f"Hello, {args.name}")

import csv

with open("data.csv") as f:
    reader = csv.DictReader(f)
    for row in reader:
        print(row["username"], row["score"])

import re

text = "Email: test@example.com"
match = re.search(r"\w+@\w+\.\w+", text)
print(match.group())  # test@example.com

def bad_append(x, data=[]):
    data.append(x)
    return data

print(bad_append(1))    # [1]
print(bad_append(2))    # [1, 2]  <-- неожиданно!


def good_append(x, data=None):
    if data is None:
        data = []
    data.append(x)
    return data

print(good_append(1))   # [1]
print(good_append(2))   # [2]

class User:
    def __init__(self, name):
        self.name = name

# Обычный объект
u = User("Alice")

# Функция, которую хотим "подмешать"
def greet(self):
    return f"Hello, {self.name}!"

# Вклиниваем метод в класс
User.greet = greet

print(u.greet())  # Hello, Alice!