python - pandas python 中的 SQL 查询

Question

我正在 python pandas 中编写 SQL 查询:

import pandas as pd
from pandas import DataFrame, read_csv
import numpy as np
from pandasql import sqldf
pysqldf=lambda q:sqldf(q,globals())
rolup = pysqldf(u"select MasterUserId,DeviceUsed,hcluster, count(MasterUserId) as Tot_Rec, sum(Visits),sum(PV),sum(TimeSpent) from clstrd_data group by MasterUserId,DeviceUsed,hcluster;")

错误:

sqlite3.ProgrammingError: You must not use 8-bit bytestrings unless you use a text_factory that can interpret 8-bit bytestrings (like text_factory = str). It is highly recommended that you instead just switch your application to Unicode strings.

如何切换到 Unicode 字符串？我使用的是python2.7。

Answer 1

根据python unicode howto :

In Python source code, Unicode literals are written as strings prefixed with the ‘u’ or ‘U’ character: u'abcdefghijk'

换句话说，您的脚本应为:

import pandas as pd
from pandas import DataFrame, read_csv
import numpy as np
from pandasql import sqldf
pysqldf=lambda q:sqldf(q,globals())
rolup = pysqldf(u"select MasterUserId,DeviceUsed,hcluster, count(MasterUserId) as Tot_Rec, sum(Visits),sum(PV),sum(TimeSpent) from clstrd_data group by MasterUserId,DeviceUsed,hcluster;")

希望有帮助。