snowflakedb
SNOW-680197: cursor.execute can return None which requires checking
What is the current behavior?
SnowflakeCursor execute returns SnowflakeCursor | None.
This means every excecute needs to be checked for None. eg:
c = cur.execute("select * from mytable")
if c:
results = c.fetchone()
If the check isn't performed then pyright/vscode will error with
"fetchone" is not a known member of "None" (reportOptionalMemberAccess)
Or the application will fail at runtime.
What is the desired behavior?
cursor.execute does not return None for any cases, therefore avoiding the need for a None check.
How would this improve snowflake-connector-python?
This would enable the more fluent syntax without the need for a check:
cur.execute("select * from mytable").fetchone()
References, Other Background
From the pyright docs:
reportOptionalMemberAccess [boolean or string, optional]: Generate or suppress diagnostics for an attempt to access a member of a variable with an Optional type. The default value for this setting is 'error'.
According to the function documentation, None does have legit meaning, so I'm not sure if removing it is the correct behavior.
https://github.com/snowflakedb/snowflake-connector-python/blob/98677d56a6031b8bafb2765a1a2d2976397b0308/src/snowflake/connector/cursor.py#L624-L625
Yeh None is returned when the caller provides an empty command:
https://github.com/snowflakedb/snowflake-connector-python/blob/98677d56a6031b8bafb2765a1a2d2976397b0308/src/snowflake/connector/cursor.py#L643
Could this be a ValueError exception instead perhaps?
From the python docs:
exception ValueError Raised when an operation or function receives an argument that has the right type but an inappropriate value, and the situation is not described by a more precise exception such as IndexError.
Could this be a ValueError exception instead perhaps?
This is going to be a behavior change, but it might not be a bad idea. WDYT? @sfc-gh-mkeller
