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Modules/_sqlite/module.c

Source:

cpython 3.14 @ ab2d84fe1023/Modules/_sqlite/module.c

sqlite3 wraps the SQLite C library. The module is organized across several files: module.c (registration), connection.c (sqlite3.Connection), cursor.c (sqlite3.Cursor), row.c (sqlite3.Row), and statement.c (prepared statements).

Map​

FileRole
module.cModule registration, connect(), constants
connection.cConnection: open, close, execute, commit, rollback, create_function
cursor.cCursor: execute, executemany, fetchone, fetchall, description
statement.cPrepared statement lifecycle
row.cRow factory: column-name access for query rows
microprotocols.cDB-API 2 adaptation protocol

Reading​

connect​

// CPython: Modules/_sqlite/module.c:68 pysqlite_connect
static PyObject *
pysqlite_connect(PyObject *self, PyObject *args, PyObject *kwargs)
{
    ...
    /* Opens database:
       database: str (":memory:" for in-memory)
       timeout: float (default 5.0)
       detect_types: int (0 = none, PARSE_DECLTYPES | PARSE_COLNAMES)
       isolation_level: str or None
       check_same_thread: bool (default True)
       factory: type (default Connection)
       cached_statements: int (default 128)
    */
    return pysqlite_connection_create(pysqlite_ConnectionType, args, kwargs);
}

Cursor.execute​

// CPython: Modules/_sqlite/cursor.c pysqlite_cursor_execute

Calls sqlite3_prepare_v2 to parse the SQL, binds parameters (Python objects to SQLite types via the adaptation protocol), then calls sqlite3_step to begin execution.

Python objects are mapped to SQLite types: None -> NULL, int -> INTEGER, float -> REAL, str -> TEXT, bytes -> BLOB.

Transaction management​

Connection.isolation_level controls implicit transaction handling. When set (non-None), DML statements (INSERT, UPDATE, DELETE) automatically begin a transaction. When None, the connection is in autocommit mode.

create_function​

# CPython: Lib/sqlite3/connection.py create_function
conn.create_function("mysum", 2, lambda a, b: a + b)

Registers a Python callable as a SQLite user-defined function. SQLite calls it via sqlite3_create_function_v2 with a callback that marshals C types to Python and back.

Row factory​

sqlite3.Row implements the __getitem__ protocol for both integer indices and case-insensitive column names, allowing row['columnname'] access.

gopy notes​

Status: not yet ported. Go has database/sql with modernc.org/sqlite (pure-Go SQLite) or github.com/mattn/go-sqlite3 (cgo). A gopy sqlite3 port would wrap database/sql with a Python DB-API 2.0 compatible interface: Connection, Cursor, Row types with the same attribute names.