Stupid SQLite3 handler

sqlite3db.py

import re
import sqlite3


class SQLite3DB:
    _IDENTIFIER_RE = re.compile(r'^[a-zA-Z_]\w*$')

    def __init__(self, filename):
        self._con = sqlite3.connect(filename, isolation_level=None)
        self._con.row_factory = sqlite3.Row

    def _validate_args(self, *indentifiers):
        for idfr in indentifiers:
            if not self._IDENTIFIER_RE.match(idfr):
                raise ValueError('Bad indentifier: ' + idfr)

    def insert(self, table, **kwargs):
        keys = kwargs.keys()
        self._validate_args(table, *keys)

        column_field = ', '.join(keys)
        placeholder_field = ', '.join(':' + k for k in keys)
        sql = '''
            INSERT INTO {table} ({column_field}) VALUES ({placeholder_field})
        '''.format(
            table=table,
            column_field=column_field,
            placeholder_field=placeholder_field,
        )
        self._con.execute(sql, kwargs)

    def select(self, table, columns, **kwargs):
        keys = kwargs.keys()
        args = columns + tuple(keys)
        self._validate_args(table, *args)

        column_field = ', '.join(columns)
        sql = '''
            SELECT {column_field} FROM {table}
        '''.format(
            table=table,
            column_field=column_field,
        )
        if keys:
            cond_field = ' AND '.join('{0} == :{0}'.format(k) for k in keys)
            sql += '''
                WHERE {cond_field}
            '''.format(
                cond_field=cond_field,
            )
        return self._con.execute(sql, kwargs)