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Date: Mon, 23 Feb 2015 13:29:28 +1100
Subject: Unrecognized backslash escapes in string literals
From: Chris Angelico <rosuav@gmail.com>
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Xref: csiph.com comp.lang.python:86178

In Python, unrecognized escape sequences are treated literally,
without (as far as I can tell) any sort of warning or anything. This
can mask bugs, especially when Windows path names are used:

>>> 'C:\sqlite\Beginner.db'
'C:\\sqlite\\Beginner.db'
>>> 'c:\sqlite\beginner.db'
'c:\\sqlite\x08eginner.db'

To a typical Windows user, the two strings should be equivalent - case
insensitive file names, who cares whether you say "Beginner" or
"beginner"? But to Python, one of them will happen to work, the other
will fail badly.

Why is it that Python interprets them this way, and doesn't even give
a warning? What happened to errors not passing silently? Or, looking
at this the other way: Is there a way to enable such warnings/errors?
I can't see one in 'python[3] -h', but if there's some way elsewhere,
that would be a useful thing to recommend to people (I already
recommend running Python 2 with -tt).

ChrisA