Use raw strings for regex

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

src/univers/gentoo.py

@@ -10,7 +10,7 @@
 
 suffix_regexp = re.compile("^(alpha|beta|rc|pre|p)(\\d*)$")
 
-revision_regexp = re.compile(".*(-r\d+)")
+revision_regexp = re.compile(r".*(-r\d+)")
 
 suffix_value = {"pre": -2, "p": 1, "alpha": -4, "beta": -3, "rc": -1}
 

src/univers/versions.py

@@ -216,7 +216,7 @@ def __lt__(self, other):
 @attr.s(frozen=True, init=False, order=False, eq=False, hash=True, repr=False)
 class GentooVersion(BaseVersion):
     scheme = "ebuild"
-    version_re = re.compile("^(?:\d+)(?:\.\d+)*[a-zA-Z]?(?:_(p(?:re)?|beta|alpha|rc)\d*)*$")
+    version_re = re.compile(r"^(?:\d+)(?:\.\d+)*[a-zA-Z]?(?:_(p(?:re)?|beta|alpha|rc)\d*)*$")
 
     def __init__(self, version_string):
         version_string = remove_spaces(version_string)