Python自动生成sql语句

#!usr/bin/env python# coding=utf-8def auto_insert_sql(objs, table=None, charset='UTF-8'):    """    自动生成insert SQL语句，如果obj为对象列表，则根据第一个对象生成SQL语句。    @objs 对象或对象列表    @table 数据表名    @charset 数据库编码    @return (SQL语句，转换后的对象或对象列表)    """    is_batch = isinstance(objs, list)    if not objs:        return (None, []) if is_batch else (None, None)    obj = objs[0] if is_batch else objs    obj_li = objs if is_batch else [objs]    # 解析表名    if not table:        table = obj.__class__.__name__    # 解析字段 和 转换数据    cols = []    row_li = []    if hasattr(obj, '__iter__'):  # dict        # 解析字段        for k in obj:            cols.append(k)        # 转换数据        for obj in obj_li:            row = {}            for k in cols:                v = obj[k]                row[k] = v.encode(charset) if isinstance(v, unicode) else v            row_li.append(row)    elif hasattr(obj, '__dict__'):  # object        for i, (k, v) in enumerate(obj.__dict__.items()):            cols.append(k)        for obj in obj_li:            row = {}            for k in cols:                v = getattr(obj, k)                row[k] = v.encode(charset) if isinstance(v, unicode) else v            row_li.append(row)    elif hasattr(obj, 'ListFields'):  # Google Protocol Buffer        for field, v in obj.ListFields():            cols.append(field.name)        for obj in obj_li:            row = {}            for k in cols:                v = getattr(obj, k) if obj.HasField(k) else None                row[k] = v.encode(charset) if isinstance(v, unicode) else v            row_li.append(row)    else:        raise Exception("couldn't parse object: %s" % obj)    # 生成SQL语句    if not cols:        raise Exception("no colume found in object: %s" % obj)    sql_prefix = ['insert into ', table, ' (']    sql_suffix = [') values(']    for i, k in enumerate(cols):        sql_prefix.append(', %s' % k if i > 0 else k)        sql_suffix.append(', :%s' % k if i > 0 else ':%s' % k)    sql_suffix.append(')')    sql_prefix.extend(sql_suffix)    sql = ''.join(sql_prefix)    # --------------------------------------------------    return (sql, row_li) if is_batch else (sql, row_li[0])class A(object):    def __init__(self):        self.c1 = 0        self.c2 = 0        self.c3 = 3def main():    # a = A()    a = {'a': 1, 'b': 2}    print auto_insert_sql([a], 'test_table')if __name__ == '__main__':    main()