Question

我将查询导入pandas数据框，然后创建一个名为hindex的结果数据框，以导入到我的数据库表中，如下所示：

import sqlite3
import numpy as np
import pandas as pd

#access the database created
db = sqlite3.connect('test/publications')

df = pd.read_sql("select AuthorID as ID, citations from publications as p join authors_publications as a on p.ID=a.PaperID order by AuthorID, citations desc", db)

df2 = df.sort(['ID','Citations'],ascending=['Citations','ID'])
groups = df2.groupby('ID')
ind2 = np.array([np.arange(len(g))+1 for g in groups.groups.itervalues()])
df2['newindex'] = np.hstack(ind2)
df2['condition'] = df2['Citations']>=df2['newindex']
hindex = df2.groupby('ID').sum()['condition']

hindex.to_sql('authors_hindex', db, flavor='sqlite', if_exists='replace', index=True)

我之前使用过to_sql并且它有效。不知道为什么它不在这里。我收到以下错误：

AttributeError                     Traceback (most recent call last)
<ipython-input-4-0748af5dad1d> in <module>()
     43 
     44 print hindex
---> 45 hindex.to_sql('authors_hindex', db, flavor='sqlite', if_exists='replace', index=True)
     46 

/usr/lib/python2.7/dist-packages/pandas/core/generic.pyc in __getattr__(self, name)
   1813                 return self[name]
   1814             raise AttributeError("'%s' object has no attribute '%s'" %
-> 1815                                  (type(self).__name__, name))
   1816 
   1817     def __setattr__(self, name, value):

AttributeError: 'Series' object has no attribute 'to_sql'

Answer 1

试试这个：

hindex = df2.groupby('ID').sum()[['condition']]

所以使用双[[]]将返回一个df

您的原始行：hindex = df2.groupby('ID').sum()['condition']返回了一个系列，但这确实有一个to_sql方法，但不清楚为什么会失败。

AttributeError：'Series'对象没有属性'to_sql'

1 个答案: