On 11/27/2013 8:57 PM, Victor Hooi wrote:
[sorry if the re-wrapping mis-formats anything]
I'm running pep8
Ah yes, the module that turns PEP8 into the straightjacket it explicitly
says it is not meant to be.
across my code,
We mostly to not change existing stdlib modules to conform unless they
are being edited anyway for fixes and features.
and getting warnings about my long lines (> 80 characters).
You are free to ignore such
I'm wonder what's the recommended way to handle the below cases, and
fit under 80 characters.
First example - multiple context handlers:
with open(self.full_path, 'r') as input, open(self.output_csv, 'ab')
as output:
and in my case, with indents, the 80-character marks is just before
the ending "as output".
What's the standard recognised way to split this across multiple
lines, so that I'm under 80 characters?
I believe () does not work, so put \ after 'input,'.
I can't just split after the "as input," as that isn't valid syntax,
and there's no convenient parentheses for me to split over.
Is there a standard Pythonic way?
Second example - long error messages:
self.logger.error('Unable to open input or output file - %s. Please
check you have sufficient permissions and the file and parent
directory exist.' % e)
I can use triple quotes:
self.logger.error( """Unable to open input or output file - %s.
Please check you have sufficient permissions and the file and parent
directory exist.""" % e)
However, that will introduce newlines in the message, which I don't
want.
I can use backslashes:
self.logger.error( 'Unable to open input or output file - %s. Please
check you\ have sufficient permissions and the file and parent
directory\ exist.' % e)
which won't introduce newlines.
Or I can put them all as separate strings, and trust Python to glue
them together:
Such gluing in a documented feature and I think you can trust it to not
disappear (for at least a decade ;-).
self.logger.error( 'Unable to open input or output file - %s. Please
check you' 'have sufficient permissions and the file and parent
directory' 'exist.' % e)
Which way is the recommended Pythonic way?
Third example - long comments:
""" NB - We can't use Psycopg2's parametised statements here, as that
automatically wraps everything in single quotes. So
s3://my_bucket/my_file.csv.gz would become
s3://'my_bucket'/'my_file.csv.gz'. Hence, we use Python's normal
string formating - this could potentially exposes us to SQL injection
attacks via the config.yaml file. I'm not aware of any easy ways
around this currently though - I'm open to suggestions though. See
http://stackoverflow.com/questions/9354392/psycopg2-cursor-execute-with-sql-query-parameter-causes-syntax-error
for further information. """
In this case, I'm guessing a using triple quotes (""") is a better
idea with multi-line comments, right?
Either are ok.
However, I've noticed that I can't seem to put in line-breaks inside
the comment without triggering a warning. For example, trying to put
in another empty line in between lines 6 and 7 above causes a
warning.
Blank lines are normal in triple-quoted strings and recommended for
docstrings longer than a line. So I am puzzled as to your problem.
Also, how would I split up the long URLs?
Don't if you can possibly avoid it.
Breaking it up makes it annoying to use the URL.
Yep.
Thoughts?
Some urls, especially long ones, have extra tracking/query junk that can
be removed while still pointing to the page.
--
Terry Jan Reedy
--
https://mail.python.org/mailman/listinfo/python-list
