PyYAML 错误：“yaml.scanner.ScannerError：此处不允许映射值”

Question

解析 YAML 时出现奇怪的错误：

yaml.scanner.ScannerError: mapping values are not allowed here

根据YAML Lint，我尝试读取的 YAML 文件是有效的

另一个奇怪的事情是它在我的笔记本电脑（Arch Linux）上运行良好，但在服务器（Ubuntu）上运行不正常。尽管两台机器上的 PyYAML 版本是相同的。

我在 stackoverflow 上看到过 其他帖子，其中人们缺少冒号后面的空格，但我没有缺少任何空格。

这是完整的 YAML 文件：

yaml.scanner.ScannerError: mapping values are not allowed here

这是完整的堆栈跟踪：

Traceback (most recent call last):
  File "/usr/local/bin/someproject", line 9, in <module>
    load_entry_point('someproject==0.0.1', 'console_scripts', 'someproject')()
  File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/__init__.py", line 19, in main
    pipeline.Pipeline(parser.parse_args().scriptfile).start()
  File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/pipeline/pipeline.py", line 20, in __init__
    self._raw_pipeline = self._parse_yaml(yamlscript)
  File "/usr/local/lib/python3.4/dist-packages/someproject-0.0.1-py3.4.egg/someproject/pipeline/pipeline.py", line 55, in _parse_yaml
    data = yaml.load(yamlscript)
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/__init__.py", line 72, in load
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/constructor.py", line 35, in get_single_data
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 36, in get_single_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 55, in compose_document
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 133, in compose_mapping_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 82, in compose_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 111, in compose_sequence_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 133, in compose_mapping_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 84, in compose_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/composer.py", line 127, in compose_mapping_node
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/parser.py", line 98, in check_event
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/parser.py", line 428, in parse_block_mapping_key
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 116, in check_token
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 220, in fetch_more_tokens
  File "/usr/local/lib/python3.4/dist-packages/PyYAML-3.11-py3.4-linux-x86_64.egg/yaml/scanner.py", line 580, in fetch_value
yaml.scanner.ScannerError: mapping values are not allowed here
  in "./test1.yaml", line 3, column 93

Answer 1

冒号后面没有缺少任何空格，以 开头的行中有太多input: /home/omnibrain/projects/company/data/data.csv空格。这就是为什么您会看到第 3 行第 93 列

整行内容如下：

      input: /home/omnibrain/projects/company/data/data.csv                           output: some_data

它还应该有一些有趣的字符扰乱你的显示，就像通常你会看到一个字符串一样

...                           output: some_data

下面的映射不允许在这里。

如果文件看起来相同但实际上不同，例如从一个终端复制并粘贴到另一个终端后，通常会出现这种差异。或者粘贴到 YAMLlint 等网站后。

在两个系统上生成一个md5sum文件以检查它们是否确实相同。od -c在 YAML 文件上使用来检查它是否有奇怪的字符。