我能插入一条线吗拉梅尔亚姆勒的评论地图？

Question

我知道这与this SO question有关，但我最关心的是这是否会影响诸如保留的注释之类的事情。在

import ruamel.yaml as yaml

yaml_str = """\
first_name: Art
occupation: Architect  # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
"""

data = yaml.load(yaml_str, Loader=yaml.RoundTripLoader)

# I'd like to extend CommentedMap so that I can do something like:
data.insert(1, 'last_name', 'Vandelay')

print(yaml.dump(data, Dumper=yaml.RoundTripDumper))

应输出： ^{pr2}$ 应不输出：

first_name: Art
last_name: Vandelay    # This is an occupation comment
occupation: Architect
about: Art Vandelay is a fictional character that George invents...

Answer 1

在Python2.7和Python3.X上，至少拉梅尔亚姆勒0.11.11，这很好：

import ruamel.yaml

yaml_str = """\
first_name: Art
occupation: Architect  # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
"""

data = ruamel.yaml.round_trip_load(yaml_str)
data.insert(1, 'last name', 'Vandelay')

print(ruamel.yaml.round_trip_dump(data))

给出：

^{pr2}$

因为行尾注释与CommentedMap中的行的键相关联。（在Linux Mint上使用Python 2.7.11拉梅尔亚姆勒0.11.10.）

这在旧版本的上不起作用拉梅尔亚姆勒使用Python3作为.insert()是成熟的ruamel.ordereddict的一个特性，而标准库中的OrderedDict没有这种方法。因此，您需要将.insert()函数移植到CommentedMap上：

import ruamel.yaml
from ruamel.yaml.comments import CommentedMap
from ruamel.yaml.compat import ordereddict

yaml_str = """\
first_name: Art
occupation: Architect  # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...
"""

def com_insert(self, pos, key, value, comment=None):
    od = ordereddict()
    od.update(self)
    for k in od:
        del self[k]
    for index, old_key in enumerate(od):
        if pos == index:
            self[key] = value
        self[old_key] = od[old_key]
    if comment is not None:
        self.yaml_add_eol_comment(comment, key=key)

CommentedMap.insert = com_insert

data = ruamel.yaml.round_trip_load(yaml_str)
data.insert(1, 'last name', 'Vandelay', comment="new key")

print(ruamel.yaml.round_trip_dump(data))

在Python3上给出：

first_name: Art
last name: Vandelay    # new key
occupation: Architect  # This is an occupation comment
about: Art Vandelay is a fictional character that George invents...

请注意，insert()有一个可选参数，允许您为新插入的键值对指定注释。上面的操作是因为从CommentedMap中删除一个键并不会删除与该键相关联的注释。所以我临时将旧的键值对存放在od 复制并在后面插入新的值

上面的insert，带注释，已添加到拉梅尔亚姆勒0.11.11用于 Python 2和Python 3

---

.round_trip_load()相当于.load(...., Loader=ruamel.yaml.RoundTripLoader, ...)，而{}相当于`.dump（…，Dumper）=ruamel.yaml.roundtripper公司，允许\-unicode=True，…）