Python pandas从mysql获取最大值

Question

我执行语句

sequence = pd.read_sql_query('SELECT MAX(_SequenceNumber) AS sequence_number FROM betting.betting', database)

获取数据框

   sequence_number
0             4495

我不知道如何得到 4495 我正在尝试类似的东西

sequence = dataframe.iloc[0]

还是不给我

sequence = 4495

你能帮我一下吗？

Answer 1

我认为你可以使用at或iat对于 fast scalar value getting :

print dataframe.at[0, 'sequence_number']
4495

print dataframe.sequence_number.iat[0]
4495

print type(dataframe.at[0, 'sequence_number'])
<type 'numpy.int64'>

print type(dataframe.sequence_number.iat[0])
<type 'numpy.int64'>