contrib: enforce wrapping too-long lines with () instead of \ This is the style I prefer, and an anecdotal exploration of styles recommended in style guides etc. Further, to quote pep8: > The preferred way of wrapping long lines is by using Python's implied > line continuation inside parentheses, brackets and braces. Long lines > can be broken over multiple lines by wrapping expressions in > parentheses. These should be used in preference to using a backslash > for line continuation. So I think this is a virtuous change. Differential Revision: https://phab.mercurial-scm.org/D5995

--- a/contrib/check-code.py	Wed Feb 20 18:02:28 2019 -0500
+++ b/contrib/check-code.py	Sun Jan 13 20:27:00 2019 -0500
@@ -233,6 +233,7 @@
 
 pypats = [
   [
+    (r'\\$', 'Use () to wrap long lines in Python, not \\'),
     (r'^\s*def\s*\w+\s*\(.*,\s*\(',
      "tuple parameter unpacking not available in Python 3+"),
     (r'lambda\s*\(.*,.*\)',