国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

? ??? ?? ??? ???? Python?? ??? SQLite ????? ??? ??

Python?? ??? SQLite ????? ??? ??

Dec 10, 2024 pm 02:29 PM

Building a Simple SQLite Library Manager in Python

Python?? ??? SQLite ????? ??? ??

???? ????? ???? ?? ?? ????? ?? ???? SQLite? ? ??? ???? ??? ????. ? ??????? ???? ???? ?? ???? ??? ? ??? ??? ??????? ???? ?? Python ??????? ?????.

? ??? ??? ?? ??? ?? ? ????.

  • SQLite ??????? ???? ?????.
  • ??? ????? ??? ?????.
  • ?? ??? ?? ???? ?????.

1. ?????? ? ??? ??

SQLite ?????? ??? ???? books ???? ???? ??? ??? ?????. ? ??? ??, ??, ISBN, ?? ?? ? ??? ?? ??? ????.

import sqlite3
import os

def create_library_database():
    """Creates the library database if it doesn't already exist."""
    db_name = "library.db"

    if not os.path.exists(db_name):
        print(f"Creating database: {db_name}")
        conn = sqlite3.connect(db_name)
        cursor = conn.cursor()
        cursor.execute('''
            CREATE TABLE IF NOT EXISTS books (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                title TEXT,
                author TEXT,
                isbn TEXT UNIQUE,
                published_date DATE,
                genre TEXT
            )
        ''')
        conn.commit()
        conn.close()
    else:
        print(f"Database already exists: {db_name}")

??????? ?????? ?? ??? ?????.

create_library_database()

??? ?? ??? ??? ?? ? ???? ??? library.db ??? ???? ????? ?????.


  1. ??????? ?? ??

??? ??? ? isbn ??? ???? ?? ??? ???? ??? ??? ???. ??? ???? ???? ?? SQLite? INSERT OR IGNORE ?? ???????.

?? ?? ??? ??? ????.

def insert_book(book):
    """
    Inserts a book into the database. If a book with the same ISBN already exists,
    the insertion is ignored.
    """
    conn = sqlite3.connect("library.db")
    cursor = conn.cursor()

    try:
        # Insert the book. Ignore the insertion if the ISBN already exists.
        cursor.execute('''
            INSERT OR IGNORE INTO books (title, author, isbn, published_date, genre)
            VALUES (?, ?, ?, ?, ?)
        ''', (book["title"], book["author"], book["isbn"], book["published_date"], book["genre"]))
        conn.commit()

        if cursor.rowcount == 0:
            print(f"The book with ISBN '{book['isbn']}' already exists in the database.")
        else:
            print(f"Book inserted: {book['title']} by {book['author']}")

    except sqlite3.Error as e:
        print(f"Database error: {e}")
    finally:
        conn.close()

? ??? INSERT OR IGNORE SQL ?? ???? ?? ??? ????? ????? ???.


?3. ?? ?? ??

?????? ?? ???? insert_book ??? ???? ?????.

books = [
    {
        "title": "To Kill a Mockingbird",
        "author": "Harper Lee",
        "isbn": "9780061120084",
        "published_date": "1960-07-11",
        "genre": "Fiction"
    },
    {
        "title": "1984",
        "author": "George Orwell",
        "isbn": "9780451524935",
        "published_date": "1949-06-08",
        "genre": "Dystopian"
    },
    {
        "title": "Pride and Prejudice",
        "author": "Jane Austen",
        "isbn": "9781503290563",
        "published_date": "1813-01-28",
        "genre": "Romance"
    }
]

for book in books:
    insert_book(book)

? ??? ???? ?? ??? ??????? ?????. ?? ???? ??? ?? ???? ?????.

The book with ISBN '9780061120084' already exists in the database.
The book with ISBN '9780451524935' already exists in the database.
The book with ISBN '9781503290563' already exists in the database.

4. ?? ??

??????? ???? ?? ???? ??? ? ????. ?? ??, ???? ?? ?? ?? ?????:

def fetch_all_books():
    conn = sqlite3.connect("library.db")
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM books")
    rows = cursor.fetchall()
    conn.close()
    return rows

books = fetch_all_books()
for book in books:
    print(book)

??

?? Python ? ?? ??? ??? ????? ?? ???? ??? ???? ??? ? ?? ???? ????? ???? ????. SQLite? INSERT OR IGNORE? ?? ?? ??? ????? ??? ?? ???? ????? ??? ??? ?????.

??? ?? ???? ? ????? ???? ?????.

  • ???? ???? ?? ?????.
  • ?? ??? ???? ????.
  • ?? ??.

???? ??? ?? ?????? ?

? ??? Python?? ??? SQLite ????? ??? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!

? ????? ??
? ?? ??? ????? ???? ??? ??????, ???? ?????? ????. ? ???? ?? ???? ?? ??? ?? ????. ???? ??? ???? ???? ??? ?? admin@php.cn?? ?????.

? AI ??

Undresser.AI Undress

Undresser.AI Undress

???? ?? ??? ??? ?? AI ?? ?

AI Clothes Remover

AI Clothes Remover

???? ?? ???? ??? AI ?????.

Video Face Swap

Video Face Swap

??? ??? AI ?? ?? ??? ???? ?? ???? ??? ?? ????!

???

??? ??

???++7.3.1

???++7.3.1

???? ?? ?? ?? ???

SublimeText3 ??? ??

SublimeText3 ??? ??

??? ??, ???? ?? ????.

???? 13.0.1 ???

???? 13.0.1 ???

??? PHP ?? ?? ??

???? CS6

???? CS6

??? ? ?? ??

SublimeText3 Mac ??

SublimeText3 Mac ??

? ??? ?? ?? ?????(SublimeText3)

???

??? ??

?? ????
1783
16
Cakephp ????
1728
56
??? ????
1577
28
PHP ????
1442
31
???
Python? Unittest ?? Pytest ??? ??? ??? ??? ? ???? ?????? Python? Unittest ?? Pytest ??? ??? ??? ??? ? ???? ?????? Jun 19, 2025 am 01:10 AM

Python? Unittest ? Pytest? ??? ? ???? ??, ?? ? ??? ????? ? ?? ?? ???? ??? ??? ?????. 1. ??? ??? ?? ??? ???? ??? ??? ??? ?????. UnitTest? ??? ??? ???? ???? Test \ _? ???? ???? ?????. Pytest? ? ?????. Test \ _?? ???? ?? ? ??????. 2. ??? ?? ?? ? ?? ? ??? ??? ????. UnitTest? Assertequal, AssertTrue ? ?? ??? ???? ?? Pytest? ??? Assert ?? ???? ?? ?? ??? ???? ?????. 3. ?? ??? ?? ? ?? ????? ????? ????.

Numpy ? Pandas? ?? ??????? ??? ?? ? ??? Python? ??? ??? ? ????? Numpy ? Pandas? ?? ??????? ??? ?? ? ??? Python? ??? ??? ? ????? Jun 19, 2025 am 01:04 AM

pythonisidealfordataanalysisduetonumpyandpandas.1) numpyexcelsatnumericalcomputationsfast, multi-dimensionalArraysandectorizedOferationsLikenp.sqrt ()

?? ????? ???? ???? Python?? ??? ?????? ?? ????? ???? ???? Python?? ??? ?????? Jun 20, 2025 am 12:57 AM

?? ????? (DP)? ??? ??? ? ??? ?? ??? ??? ??? ? ??? ??? ?? ??? ???? ??? ????? ??????. ? ?? ?? ??? ????. 1. ??? (??) : ??? ?? ??? ???? ??? ???? ?? ??? ??????. 2. ??? (?) : ?? ???? ???? ????? ?????. ???? ???, ?? ?? ?? ?? ??/?? ?, ??? ??? ?? ?? ?? ??? ??? ????? ?????. ?????? ????? ?? ???? ?? ??? ? ???, ?? ??? ???? ?? ?? ??? ???? ??? ???? ????? ???? ???????.

__iter__ ? __next__? ???? ????? ??? ?? ???? ??? ??? ? ????? __iter__ ? __next__? ???? ????? ??? ?? ???? ??? ??? ? ????? Jun 19, 2025 am 01:12 AM

??? ?? ???? ????? ????? __iter_ ? __next__ ???? ???????. ① __iter__ ???? ??? ? ?? ??? ???? ??? ?? ?? ??? ?????. ② __next__ ???? ? ??? ?? ????, ?? ??? ??? ????, ? ?? ??? ??? stopiteration ??? ??????. status ??? ???? ??????? ?? ??? ??? ?? ?? ??? ???????. pile ?? ?? ???? ?? ??? ?? ? ??? ?? ? ??? ?????? ?????. simple ??? ??? ?? ?? ??? ?? ???? ???? ?? ??? ? ??? ?? ????? ???? ??? ??? ???????.

Python ????? ??? ???? ??? ??? ?? ?? ??? ?????? Python ????? ??? ???? ??? ??? ?? ?? ??? ?????? Jun 19, 2025 am 01:09 AM

Python? ?? ???? ?? ???, ?? ?? ????, ?? ???? ?? ? AI/ML ??? ???? ??? ?????. ??, Cpython? ???? ????? ?? ??, ?? ?? ??? ? ?? ? ?? ??? ?? ??? ??????. ??, ??? ????? ?? ?? ? ?? ??? ????? ?? ?? ? ? ??? ?? ?????. ??, Pyscript ? Nuitka? ?? ?? ???? ??? ??? ?? ??? ?????. ?????, AI ? ??? ?? ??? ?? ???? ??? ?? ???????? ???? ?? ? ??? ?????. ??? ??? Python? ??? ??? ????? ???? ?? ??? ???? ??? ?????.

??? ???? ????? ???? ?????? ??? ?????? ??? ???? ????? ???? ?????? ??? ?????? Jun 20, 2025 am 12:56 AM

Python? ?? ??? ???? ?????? ????, ????? ? ?? ??????? ???? ? ??? ??? ???? ?? ??? ?????. ?? TCP ??? ????? Socket.Socket ()? ???? ??? ??? ?? ? ??? ????? .listen ()? ???? ??? ?? .accept ()? ?? ????? ??? ???????. TCP ?????? ????? ?? ??? ??? ??? ????? .connect ()? ?? ? ?? .sendall ()? ???? ???? ??? .recv ()? ?? ??? ??????. ?? ?????? ????? 1. ??? : ??? ??? ? ???? ??? ? ????. 2. ??? I/O : ?? ??, Asyncio ?????? ? ??? ??? ?? ? ? ????. ???? ? ?

??? ???? ??? ??? ???? ??? Jul 05, 2025 am 02:58 AM

???? Python ?? ?? ?????? ?? ????, "??? ?????, ?? ??"? ???? ??? ??? ??? ?? ??? ?????. 1. ???? ?? ? ??? ?? ?????. ?? ???? ?? ??? ???? ??? ? ? ????. ?? ??, Spoke () ?? ???? ??? ??? ?? ??? ?? ????? ?? ??? ??? ????. 2. ???? ?? ???? ??? ??? ?????? Draw () ???? ???? ????? ?? ???? ?? ??? ???? ??? ???? ?? ?? ?? ??? ????? ?? ?? ????? ?? ?????. 3. Python ?? ???? ???????. ?? ???? ??? ???? ?? ???? ??? ????? ??? ?? ???? ??? ???? ????. ??? ??? ??? ???? ? ??? "?? ??"??????. 4. ???? ? ???? ?? ??? ?????

Python?? ??? ??? ???????? Python?? ??? ??? ???????? Jun 20, 2025 am 12:51 AM

Python List ????? ?? ?? ??? [Start : End : Step] ??? ????? ??? ???? ????. 1. ?? ????? ?? ??? ?? [start : end : step]???. ??? ?? ??? (??), ?? ? ??? (???? ??)?? ??? ?? ?????. 2. ????? ???? 0?? ????? ???? ????? ??? ??? ???? ????? ??? 1? ??????. 3. my_list [: n]? ???? ? ?? n ??? ?? my_list [-n :]? ???? ??? n ??? ????. 4. My_List [:: 2]? ?? ??? ?? ?? ??? ???? ??? ??? ?? ?? ?? ??? ???? ? ????. 5. ???? ???? ? ???? ???? ????

See all articles