raise ScannerError(None, None, yaml.scanner.ScannerError: 此处不允许映射值

Question

我正在尝试更加熟悉 Python 的 .yaml 文件格式。我选择了一个基本玩具并开始玩它。但是，我最初遇到了一个问题。我搜索了解决方案并尝试了 Google 上提供的几个示例，但均未成功。 这是我的代码

test.yaml

这是我的 main.py

    import yaml
if __name__ == '__main__':

    stream = open("test.yaml", 'r')
    dictionary = yaml.load(stream)
    for key, value in dictionary.items():
        print (key + " : " + str(value))

错误

"C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\python.exe" "C:/Users/Nafees Ahmed/PycharmProjects/Code_Playing_Testing/main.py"
C:/Users/Nafees Ahmed/PycharmProjects/Code_Playing_Testing/main.py:10: YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
  dictionary = yaml.load(stream)
Traceback (most recent call last):
  File "C:/Users/Nafees Ahmed/PycharmProjects/Code_Playing_Testing/main.py", line 10, in <module>
    dictionary = yaml.load(stream)
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\__init__.py", line 114, in load
    return loader.get_single_data()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\constructor.py", line 49, in get_single_data
    node = self.get_single_node()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\composer.py", line 36, in get_single_node
    document = self.compose_document()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\composer.py", line 127, in compose_mapping_node
    while not self.check_event(MappingEndEvent):
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\parser.py", line 98, in check_event
    self.current_event = self.state()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\parser.py", line 428, in parse_block_mapping_key
    if self.check_token(KeyToken):
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\scanner.py", line 223, in fetch_more_tokens
    return self.fetch_value()
  File "C:\Users\Nafees Ahmed\AppData\Local\Programs\Python\Python38\lib\site-packages\yaml\scanner.py", line 577, in fetch_value
    raise ScannerError(None, None,
yaml.scanner.ScannerError: mapping values are not allowed here
  in "test.yaml", line 2, column 10

Answer 1

在 YAML 映射中，每个键都只有一个值。键 foo 不能同时具有标量 bar 和以 pleh: 开头的嵌套映射作为值。

目前尚不清楚您要做什么，但以下任何一种方法都可以：

# dropping the value `bar`
foo:
  pleh: help
  stuff:
    foo: bar
    bar: foo

# making `bar` a value of the nested mapping
foo:
  name: bar
  pleh: help
  stuff:
    foo: bar
    bar: foo

# assuming `bar` and `pleh` should be a single multiline value.
# this requires the explicit key marker `?`.
foo:
  ? bar
    pleh
  : help
  stuff:
    foo: bar
    bar: foo