write log messages to stderr

[finswimmer]

Hello everyone.

Describe the bug
At the moment sqlalchemy prints out messages to stdout by default, e.g when setting echo=True in create_engine. This is also stated out clearly in docs.

Messages by sqlalchemy are usually useful for diagnostics. According to https://www.gnu.org/software/libc/manual/html_node/Standard-Streams.html it is recommended to use stderr for such a purpose. This becomes more important, if the program, in which sqlalchemy is used, writes its output to stdout, as there is no (easy) way which messages are a result of the program and which one are debug messages by sqlalchemy.

Expected behavior
Messages by sqlalchemy should be printed out to stderr by default, or at least this should be configurable.

Is this the correct line that is responsable for the current behavior?

fin swimmer

[zzzeek]

hey there -

echo=True is not intended as a production-level logging facility, it's used for when you're in a Python console and want to see SQL generated quickly.

For production-quality logging, you should use Python's standard logging system. Configuration of SQLAlchemy's logging in terms of this system is described at: https://docs.sqlalchemy.org/en/13/core/engines.html#configuring-logging