danger will yamlson, danger

gistfile1.txt

$ irb
irb(main):001:0> require 'yaml'
=> true
irb(main):002:0> YAML::load_file 'test.yaml'
=> {"foo"=>"bar"}
irb(main):003:0> ^D
$ python
Python 3.6.5 (default, Apr 25 2018, 14:23:58)
[GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import 'yaml'
  File "<stdin>", line 1
    import 'yaml'
                ^
SyntaxError: invalid syntax
>>> import yaml
>>> with open("test.yaml", 'r') as stream:
...     try:
...         print(yaml.load(stream))
...     except yaml.YAMLError as exc:
...         print(exc)
...
expected a single document in the stream
  in "test.yaml", line 2, column 1
but found another document
  in "test.yaml", line 3, column 1
>>>
$ cat test.yaml
---
foo: bar
---
foo: baz