我想向一个CommentedSeq对象分配新值,以保留其流样式。但是,这样的操作导致TypeError: '<' not supported between instances of 'slice' and 'int'
。
这是否意味着CommentedSeq不支持就地分配,这是Python列表的最基本功能?
from ruamel.yaml import YAML
y = YAML()
x = y.seq([1, 2])
x.fa.set_flow_style()
x[:] = [3, 4]
451 # type: (Any, Any) -> None
452 # try to preserve the scalarstring type if setting an existing key to a new value
--> 453 if idx < len(self):
454 if isinstance(value, string_types) and \
455 not isinstance(value, ScalarString) and \
TypeError: '<' not supported between instances of 'slice' and 'int'
答案 0 :(得分:1)
您无法指出您正在使用的ruamel.yaml
的哪个版本(过时),也不能给出不使用最新版本的原因。
CommentedSeq
不是列表或其子类,它是MutableSequence
的子子类(来自collections.abc
),尽管我不会就地将切片分配称为最基本的无论如何,Python列表都是如此,MutableSequences
当然不支持它。
但是,这并不意味着CommentedSeq
不支持就地[slice]分配:
$ mktmpenv -p /opt/python/3.6/bin/python
Running virtualenv with interpreter /opt/python/3.6/bin/python
Using base prefix '/opt/python/3.6'
New python executable in /home/venv/tmp-2aaa383875f076d7/bin/python
Installing setuptools, pip, wheel...done.
This is a temporary environment. It will be deleted when you run 'deactivate'.
(tmp-2aaa383875f076d7) $ pip install ruamel.yaml
Looking in indexes: https://pypi.org/simple, http://localhost:4040/anthon/dev/+simple/
Collecting ruamel.yaml
Downloading https://files.pythonhosted.org/packages/77/51/f4314ebd8a3ec4989a3b3339a47382d87f251e5b82f2b7852a67649bc862/ruamel.yaml-0.15.64-cp36-cp36m-manylinux1_x86_64.whl (645kB)
100% |████████████████████████████████| 655kB 3.5MB/s
Installing collected packages: ruamel.yaml
Successfully installed ruamel.yaml-0.15.64
(tmp-2aaa383875f076d7) $ python
Python 3.6.6 (default, Jul 28 2018, 11:00:00)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from ruamel.yaml import YAML
>>>
>>> y = YAML()
>>> x = y.seq([1, 2])
>>> x.fa.set_flow_style()
>>> x[:] = [3, 4]
>>> print(x)
[3, 4]
>>> import sys
>>> y.dump(x, sys.stdout)
[3, 4]