ugly -> bad

cdist/hostsource.py

@@ -0,0 +1,72 @@
+# -*- coding: utf-8 -*-
+#
+# 2016 Darko Poljak (darko.poljak at gmail.com)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import fileinput
+
+
+class HostSource(object):
+    """
+    Host source object.
+    Source can be a sequence or filename (stdin if \'-\').
+    In case of filename each line represents one host.
+    """
+    def __init__(self, source):
+        self.source = source
+
+    def _process_file_line(self, line):
+        """Return host from read line or None if no host present."""
+        if not line:
+            return None
+        # remove comment if present
+        comment_index = line.find('#')
+        if comment_index >= 0:
+            host = line[:comment_index]
+        else:
+            host = line
+        # remove leading and trailing whitespaces
+        host = host.strip()
+        # skip empty lines
+        if host:
+            return host
+        else:
+            return None
+
+    def _hosts_from_sequence(self):
+        for host in self.source:
+            yield host
+
+    def _hosts_from_file(self):
+        for line in fileinput.input(files=(self.source)):
+            host = self._process_file_line(line)
+            if host:
+                yield host
+
+    def hosts(self):
+        if not source:
+            return
+
+        if isinstance(self.source, str):
+            yield from self._hosts_from_file()
+        else:
+            yield from self._hosts_from_sequence()
+
+    def __call__(self):
+        yield from self.hosts()