def iterkeys(self):
visited_keys = set()<EOL>try:<EOL><INDENT>for key in self.idb.iterkeys():<EOL><INDENT>if key not in visited_keys:<EOL><INDENT>yield key<EOL>visited_keys.add(key)<EOL><DEDENT><DEDENT><DEDENT>except (PermissionError, EnvironmentError):<EOL><INDENT>pass<EOL><DEDENT>try:<EOL><INDENT>for key in self.directory.iterkeys():<EOL><INDENT>if key not in visited_keys:<EOL><INDENT>yield key<EOL>visited_keys.add(key)<EOL><DEDENT><DEDENT><DEDENT>except (PermissionError, EnvironmentError):<EOL><INDENT>pass<EOL><DEDENT>try:<EOL><INDENT>for key in self.user.iterkeys():<EOL><INDENT>if key not in visited_keys:<EOL><INDENT>yield key<EOL>visited_keys.add(key)<EOL><DEDENT><DEDENT><DEDENT>except (PermissionError, EnvironmentError):<EOL><INDENT>pass<EOL><DEDENT>try:<EOL><INDENT>for key in self.system.iterkeys():<EOL><INDENT>if key not in visited_keys:<EOL><INDENT>yield key<EOL>visited_keys.add(key)<EOL><DEDENT><DEDENT><DEDENT>except (PermissionError, EnvironmentError):<EOL><INDENT>pass<EOL><DEDENT>
Enumerate the keys found at any scope for the current plugin.

rtype: Generator[str]