python-congressclient/congressclient/common/parseractions.py

68 lines
2.4 KiB
Python

# Copyright 2013 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
"""argparse Custom Actions"""
import argparse
class KeyValueAction(argparse.Action):
"""A custom action to parse arguments as key=value pairs
Ensures that ``dest`` is a dict
"""
def __call__(self, parser, namespace, values, option_string=None):
# Make sure we have an empty dict rather than None
if getattr(namespace, self.dest, None) is None:
setattr(namespace, self.dest, {})
# Add value if an assignment else remove it
if '=' in values:
getattr(namespace, self.dest, {}).update([values.split('=', 1)])
else:
getattr(namespace, self.dest, {}).pop(values, None)
class RangeAction(argparse.Action):
"""A custom action to parse a single value or a range of values
Parses single integer values or a range of integer values delimited
by a colon and returns a tuple of integers:
'4' sets ``dest`` to (4, 4)
'6:9' sets ``dest`` to (6, 9)
"""
def __call__(self, parser, namespace, values, option_string=None):
range = values.split(':')
if len(range) == 0:
# Nothing passed, return a zero default
setattr(namespace, self.dest, (0, 0))
elif len(range) == 1:
# Only a single value is present
setattr(namespace, self.dest, (int(range[0]), int(range[0])))
elif len(range) == 2:
# Range of two values
if int(range[0]) <= int(range[1]):
setattr(namespace, self.dest, (int(range[0]), int(range[1])))
else:
msg = ("Invalid range, %s is not less than %s" %
(range[0], range[1]))
raise argparse.ArgumentError(self, msg)
else:
# Too many values
msg = "Invalid range, too many values"
raise argparse.ArgumentError(self, msg)