Unit testing in python - Can we mock an SQL query result in python?

reno_rita

Summary : I have a method which i would like to test. This methods involves connecting the database,extracting the result (from sql query) and saving it into a data frame. I would like to know, is there a way I can mock the result retrieved from the SQL query? I tried unittest library, created a dataframe like the one received from the SQl query. But I am unable to figure out how can I pass this variable to the method while testing. Please share...

Originally asked by Trisha on Stack Exchange (stackoverflow) (CC BY-SA 4.0).

uphilltech

Great question — answering as the UphillTech team:

Let's suggest the code to test would be code_to_test.py import sqlite3 import pandas as pd def function_to_tets(): df = None try: db_connect = sqlite3.connect("address_zip.db") db_cur = db_connect.cursor() db_cur.execute(""" Select STD_ADDRESS,STD_CITY,STD_STATE from address""") sql_result = pd.read_sql_query(""" Select STD_ADDRESS,STD_CITY,STD_STATE from address""", db_connect) df = pd.DataFrame(sql_result, columns=['STD_ADDRESS', 'STD_CITY', 'STD_STATE']) print(f"The data from database is :\n {df}") db_cur.close() db_connect.close() except Exception as e: print(f"DB exception: {e}") return df So, the simple solution is to mock any call chain from sqlite3 and mock pd.read_sql_query 's...

Full answer by Ivan Reshetnikov: https://stackoverflow.stackexchange.com/a/66275470 (CC BY-SA 4.0).

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