1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
|
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 Red Hat, Inc.
#
# 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.
import inspect
class MissingArgs(Exception):
def __init__(self, missing):
self.missing = missing
def __str__(self):
if len(self.missing) == 1:
return "An argument is missing"
else:
return ("%(num)d arguments are missing" %
dict(num=len(self.missing)))
def validate_args(fn, *args, **kwargs):
"""Check that the supplied args are sufficient for calling a function.
>>> validate_args(lambda a: None)
Traceback (most recent call last):
...
MissingArgs: An argument is missing
>>> validate_args(lambda a, b, c, d: None, 0, c=1)
Traceback (most recent call last):
...
MissingArgs: 2 arguments are missing
:param fn: the function to check
:param arg: the positional arguments supplied
:param kwargs: the keyword arguments supplied
"""
argspec = inspect.getargspec(fn)
num_defaults = len(argspec.defaults or [])
required_args = argspec.args[:len(argspec.args) - num_defaults]
def isbound(method):
return getattr(method, 'im_self', None) is not None
if isbound(fn):
required_args.pop(0)
missing = [arg for arg in required_args if arg not in kwargs]
missing = missing[len(args):]
if missing:
raise MissingArgs(missing)
|
