remove the print staments in alembic.command

[sqlalchemy-bot]

Migrated issue, originally created by miniwark NA (@miniwark)

alembic.command use a few print commands to display command results. For example in current function.

If i try to use command.current in another script the version is always printed in the console.

Example script :

#!python

from alembic.config import Config
from alembic import command
    
alembic_cfg = Config('alembic.ini')
version = command.current(alembic_cfg)
if version:
   ...

This will effectively get the requested version but also print the version with may not be wanted in another script.

suggestion : return a string instead instead of using print

[sqlalchemy-bot]

Changes by miniwark NA (@miniwark):

• edited description

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

this is true that the informational commands are oriented towards being run in a console. If you want to get the current version, do this:

#!python

from alembic.migration import MigrationContext

connection = bind.connect()
ctx = MigrationContext.configure(connection)
db_head = ctx.get_current_revision()

I don't know how alembic.command could itself be changed without pushing the print statements and message formatting somewhere else. The command-line version of the tasks have to be somewhere, and that's what the "command" package is for. And I definitely wouldn't want to promote the API usage as, " to get the current version, run comand.current(), get the return value as a string, then use a regexp to pull out the number from the middle of the message". command.current is just not oriented towards API usage.

so perhaps the issue here is even promoting alembic.command as public.

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• removed labels: easy

[sqlalchemy-bot]

miniwark NA (@miniwark) wrote:

I was just in need of the revision number, i see now than this can simply be done by using directly

#!python
ScriptDirectory.get_current_head()

You then can probably close this one as "WontFix" bug.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

OK, well I made an easy enough change in 9bff65f so that at least the redirection of "print" can be done easily via the Config object, which now accepts a "stdout" parameter.

But yes, to get the current version and such, you should still use the non-command API :).

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed

[sqlalchemy-bot]

miniwark NA (@miniwark) wrote:

Thanks for the good work !