Location parsing regexes: use verbose REs

just added whitespace and comments, no semantic changes

borg/helpers.py

@@ -768,27 +768,49 @@ class Location:
     """Object representing a repository / archive location
     """
     proto = user = host = port = path = archive = None
-    # path may not contain :: (it ends at :: or string end), but may contain single colons.
+
+    # path must not contain :: (it ends at :: or string end), but may contain single colons.
     # to avoid ambiguities with other regexes, it must also not start with ":".
-    path_re = r'(?!:)(?P<path>([^:]|(:(?!:)))+)'
+    path_re = r"""
+        (?!:)                                               # not starting with ":"
+        (?P<path>([^:]|(:(?!:)))+)                          # any chars, but no "::"
+        """
     # optional ::archive_name at the end, archive name must not contain "/".
     # borg mount's FUSE filesystem creates one level of directories from
     # the archive names and of course "/" is not valid in a directory name.
-    optional_archive_re = r'(?:::(?P<archive>[^/]+))?$'
+    optional_archive_re = r"""
+        (?:
+            ::                                              # "::" as separator
+            (?P<archive>[^/]+)                              # archive name must not contain "/"
+        )?$"""                                              # must match until the end
+
     # regexes for misc. kinds of supported location specifiers:
-    ssh_re = re.compile(r'(?P<proto>ssh)://(?:(?P<user>[^@]+)@)?'
-                        r'(?P<host>[^:/#]+)(?::(?P<port>\d+))?'
-                        + path_re + optional_archive_re)
-    file_re = re.compile(r'(?P<proto>file)://'
-                         + path_re + optional_archive_re)
+    ssh_re = re.compile(r"""
+        (?P<proto>ssh)://                                   # ssh://
+        (?:(?P<user>[^@]+)@)?                               # user@  (optional)
+        (?P<host>[^:/#]+)(?::(?P<port>\d+))?                # host or host:port
+        """ + path_re + optional_archive_re, re.VERBOSE)    # path or path::archive
+
+    file_re = re.compile(r"""
+        (?P<proto>file)://                                  # file://
+        """ + path_re + optional_archive_re, re.VERBOSE)    # path or path::archive
+
     # note: scp_re is also use for local pathes
-    scp_re = re.compile(r'((?:(?P<user>[^@]+)@)?(?P<host>[^:/]+):)?'
-                        + path_re + optional_archive_re)
+    scp_re = re.compile(r"""
+        (
+            (?:(?P<user>[^@]+)@)?                           # user@  (optional)
+            (?P<host>[^:/]+):                               # host: (don't match / in host to disambiguate from file:)
+        )?                                                  # user@host: part is optional
+        """ + path_re + optional_archive_re, re.VERBOSE)    # path with optional archive
+
     # get the repo from BORG_REPO env and the optional archive from param.
     # if the syntax requires giving REPOSITORY (see "borg mount"),
     # use "::" to let it use the env var.
     # if REPOSITORY argument is optional, it'll automatically use the env.
-    env_re = re.compile(r'(?:::$)|' + optional_archive_re)
+    env_re = re.compile(r"""                                # the repo part is fetched from BORG_REPO
+        (?:::$)                                             # just "::" is ok (when a pos. arg is required, no archive)
+        |                                                   # or
+        """ + optional_archive_re, re.VERBOSE)              # archive name (optional, may be empty)
 
     def __init__(self, text=''):
         self.orig = text