python–PandasDataFrame.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.