python – Pandas DataFrame.to_sql()错误 – 不是在字符串格式化过程中转换的所有参数

Python版本 – 2.7.6

熊猫版 – 0.17.1

MysqLdb版本 – 1.2.5

DataFrame.to_sql()抛出pandas.io.sql.DatabaseError：sql执行失败’SELECT name FROM sqlite_master WHERE type =’table’AND name =？;’：不是在字符串格式化过程中转换的所有参数

Python代码段

con = MysqLdb.connect('localhost', 'root', '', 'product_Feed')
cur = con.cursor()
cur.execute("SELECT VERSION()")
connection_result = cur.fetchall()
print connection_result[0][0]     #It prints 5.5.44-0ubuntu0.14.04.1

table_column = ['A', 'B', 'C']
created_data = numpy.array([numpy.arange(10)]*3).T
df = pandas.DataFrame(data=created_data ,columns=table_column)
df.to_sql('test_table', con)

执行df.to_sql(‘test_table’,con)行时出错.

错误详情

  File "/home/yogi/yogi/mlPython/product_Feed/etl_pf/process_data.py", line 298, in render_df
    df.to_sql('test_table', con)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/core/generic.py", line 1003, in to_sql
    dtype=dtype)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 569, in to_sql
    chunksize=chunksize, dtype=dtype)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 1640, in to_sql
    table.create()
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 685, in create
    if self.exists():
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 673, in exists
    return self.pd_sql.has_table(self.name, self.schema)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 1653, in has_table
    return len(self.execute(query, [name,]).fetchall()) > 0
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 1554, in execute
    raise_with_traceback(ex)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/pandas/io/sql.py", line 1543, in execute
    cur.execute(*args)
  File "/home/yogi/yogi/mlenv/local/lib/python2.7/site-packages/MysqLdb/cursors.py", line 187, in execute
    query = query % tuple([db.literal(item) for item in args])
pandas.io.sql.DatabaseError: Execution Failed on sql 'SELECT name FROM sqlite_master WHERE type='table' AND name=?;': not all arguments converted during string formatting

I checked that pandas 0.17.1 is mostly using .format() so this error should not arise because of % formatting.

如果有人可以建议一些工作,那将是很大的帮助.我不想用cursor.execute()来试试这个

解决方法:

参数：

con：sqlAlchemy引擎或DBAPI2连接(传统模式)

使用sqlAlchemy可以使用该库支持的任何数据库.如果是DBAPI2对象,则仅支持sqlite3.

flavor：’sqlite’,默认无

从版本0.19.0开始不推荐使用：如果不使用sqlAlchemy,则’sqlite’是唯一受支持的选项.

如果使用sqlAlchemy而不是MysqLdb,那就没问题了.