Error in Reading External .SQL File #97

Hello there,

I wanted to do a data transformation in SQL using pandasql and store the query result to df_final. This is the code I used:

sqlkey = lambda q : sqldf(q,globals())
query = open('query.sql', 'r')
df_final = sqlkey(query)

And query.sql is an external .SQL file located in the same directory as my notebook. I thought the code above will run the external SQL file and store the result in df_final, but instead I got an error that said:
TypeError: expected string or bytes-like object

How should I solve this issue? Thanks in advance!