Wrapped errors should go to stderr

[neithere]

Use case

db = {'a': 1}

@wrap_errors([KeyError])
def func(key):
    return db[key]

$ app a
→ stdout: 1
→ stderr:

$ app b
→ stdout:
→ stderr: KeyError: 'b'

Motivation

The use case above implies that the command output may be redirected to another command or a file. Current implementation would have the following negative effect:

1. the user will be unaware of the error;
2. the error message will be misinterpreted as an actually retrieved value and processed, generating a further error somewhere in the toolchain.

Solution

Normal flow and catched errors should be separated in the dispatcher.

• If an error is wrapped, the result should go to the object defined as dispatch(errors_file=sys.stderr).
• The rest goes to the object defined as dispatch(output_file=sys.stdout).

Note: This issue has been automatically migrated from Bitbucket
Created by @neithere on 2013-01-14 10:18:47+00:00, last updated: 2013-01-30 01:06:04+00:00

[neithere]

Fix #37: Wrapped errors should go to stderr

→ <<cset 287d146684ac>>

Note: This comment has been automatically migrated from Bitbucket
Created by @neithere on 2013-01-30 01:06:04+00:00