update regex to match all iterations (#6839)

* update regex to match all iterations

* convert to num to match all adapters

* add comments, remove extra .

* clarify with more comments

* Update .bumpversion.cfg

Co-authored-by: Nathaniel May <nathaniel.may@fishtownanalytics.com>

---------

Co-authored-by: Nathaniel May <nathaniel.may@fishtownanalytics.com>
# Conflicts:
#	.bumpversion.cfg

.bumpversion.cfg

@@ -1,15 +1,21 @@
 [bumpversion]
-current_version = 1.2.4
-parse = (?P<major>\d+)
-	\.(?P<minor>\d+)
-	\.(?P<patch>\d+)
-	((?P<prekind>a|b|rc)
-	(?P<pre>\d+)  # pre-release version num
-	)(\.(?P<nightly>[a-z..0-9]+)
+current_version = 1.5.0a1
+
+# `parse` allows parsing the version into the parts we need to check.  There are some
+# unnamed groups and that's okay because they do not need to be audited.  If any part
+# of the version passed and does not match the regex, it will fail.
+# expected matches: `1.5.0`, `1.5.0a1`, `1.5.0a1.dev123457+nightly`
+# excepted failures: `1`, `1.5`, `1.5.2-a1`, `text1.5.0`
+parse = (?P<major>[\d]+) # major version number
+	\.(?P<minor>[\d]+) # minor version number
+	\.(?P<patch>[\d]+) # patch version number
+	(((?P<prekind>a|b|rc) # optional pre-release type
+	?(?P<num>[\d]+?)) # optional pre-release version number
+	\.?(?P<nightly>[a-z0-9]+\+[a-z]+)? # optional nightly release indicator
 	)?
 serialize =
-	{major}.{minor}.{patch}{prekind}{pre}.{nightly}
-	{major}.{minor}.{patch}{prekind}{pre}
+	{major}.{minor}.{patch}{prekind}{num}.{nightly}
+	{major}.{minor}.{patch}{prekind}{num}
 	{major}.{minor}.{patch}
 commit = False
 tag = False
@@ -23,7 +29,7 @@ values =
 	rc
 	final
 
-[bumpversion:part:pre]
+[bumpversion:part:num]
 first_value = 1
 
 [bumpversion:part:nightly]