如何在python中执行以下操作

with open('filename.txt', 'r') as file:
    content = file.read()

with open('filename.txt', 'w') as file:
    file.write('Hello, world!')

import requests

response = requests.get('https://www.example.com')
print(response.text)

import sqlite3

conn = sqlite3.connect('database.db')
cursor = conn.cursor()

cursor.execute('SELECT * FROM table')
result = cursor.fetchall()

conn.close()

import subprocess

result = subprocess.run(['ls', '-l'], capture_output=True, text=True)
print(result.stdout)