== Why is this an issue?

Typically, backslashes are seen only as part of escape sequences. Therefore, the use of a backslash outside of a raw string or escape sequence looks suspiciously like a broken escape sequence. 


Characters recognized as escape-able are: ``++abfnrtvox\'"++``


=== Noncompliant code example

[source,python]
----
s = "Hello \world."
t = "Nice to \ meet you"
u = "Let's have \ lunch"
----


=== Compliant solution

[source,python]
----
s = "Hello world."
t = "Nice to \\ meet you"
u = r"Let's have \ lunch"  // raw string
----


ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

Remove this "\", add another "\" to escape it, or make this a raw string.


'''
== Comments And Links
(visible only on this page)

=== on 4 Nov 2014, 15:59:00 Ann Campbell wrote:
pylint:W1401

=== on 17 Apr 2020, 15:18:27 Nicolas Harraudeau wrote:
Deprecating this rule.

It raises many issues and most of them look like False Positives. The most common false positives are strings  containing regular expressions. Example:

----
import re
re.sub('\(', '[', '(test)')  # False Positive
----
This rule raises 380+ issues just on Pypy.


We could try to reduce the number of false positives by focusing only on strings passed to functions which do not use backslashes, such as ``++print++`` or ``++Exception++``, but the value seems to be low. The worst that could happen is that the backslash is displayed as part of the string or that a few characters are misinterpreted:


----
In [36]: raise Exception("\.")
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
<ipython-input-36-de3222772775> in <module>
----> 1 raise Exception("\.")

Exception: \.


In [41]: raise Exception("\234324")
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
<ipython-input-41-d0bd825b64dd> in <module>
----> 1 raise Exception("\234324")

Exception: 324
----

endif::env-github,rspecator-view[]
