return values
+ def get_bool(self, param, default=None):
+ """ Extract a configuration parameter as a boolean.
+ The parameter must be one of the yaml boolean values or an
+ user error will be raised. If `default` is given, then the parameter
+ may also be missing or empty.
+ """
+ value = self.data.get(param, default)
+
+ if not isinstance(value, bool):
+ raise UsageError(f"Parameter '{param}' must be a boolean value ('yes' or 'no'.")
+
+ return value
+
+
def get_delimiter(self, default=',;'):
""" Return the 'delimiter' parameter in the configuration as a
compiled regular expression that can be used to split the names on the