python - Executing an SQL query over a pandas dataset

Question

I have a pandas data set, called 'df'.

How can I do something like below;

df.query("select * from df")

Thank you.

For those who know R, there is a library called sqldf where you can execute SQL code in R, my question is basically, is there some library like sqldf in python

Answer 1

This is not what pandas.query is supposed to do. You can look at package pandasql (same like sqldf in R )

import pandas as pd
import pandasql as ps

df = pd.DataFrame([[1234, 'Customer A', '123 Street', np.nan],
               [1234, 'Customer A', np.nan, '333 Street'],
               [1233, 'Customer B', '444 Street', '333 Street'],
              [1233, 'Customer B', '444 Street', '666 Street']], columns=
['ID', 'Customer', 'Billing Address', 'Shipping Address'])

q1 = """SELECT ID FROM df """

print(ps.sqldf(q1, locals()))

     ID
0  1234
1  1234
2  1233
3  1233

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Update 2020-07-10

update the pandasql

ps.sqldf("select * from df")