#248 Reading in safe mode after round trip does not work if value contains colon

[Anthon van der Neut]

Steps to reproduce:

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import io import ruamel.yaml my_config = '{"url": "http://example.com"}' # note the ':' in the value yaml = ruamel.yaml.YAML(typ="rt") config = yaml.load(my_config) out_io = io.StringIO() yaml.dump(config, out_io) yaml = ruamel.yaml.YAML(typ="safe") in_io = io.StringIO(out_io.getvalue()) yaml.load(in_io)

Error:

Traceback (most recent call last):
  File "foo.py", line 12, in <module>
    yaml.load(in_io)
  File "ruamel/yaml/main.py", line 325, in load
    return constructor.get_single_data()
  File "ruamel/yaml/constructor.py", line 106, in get_single_data
    node = self.composer.get_single_node()
  File "_ruamel_yaml.pyx", line 703, in _ruamel_yaml.CParser.get_single_node
  File "_ruamel_yaml.pyx", line 904, in _ruamel_yaml.CParser._parse_next_event
ruamel.yaml.scanner.ScannerError: while scanning a plain scalar
  in "<file>", line 1, column 7
found unexpected ':'
  in "<file>", line 1, column 11

Workaround is to use type="rt" in the last call to YAML.__init__

(originally posted on 2018-10-13 at 12:48:35 by Dimitri Merejkowsky <dmerejkowsky@bitbucket>)

[Anthon van der Neut]

None
(originally posted on 2018-10-13 at 12:48:51 by Dimitri Merejkowsky <dmerejkowsky@bitbucket>)

[Anthon van der Neut]

• status set to on hold

This is because the C code, coming from libyaml has errors in the scanner. Instead of using type="rt", you can do type='safe', pure=True. That will get you the Python primitives, instead of the CommentedMap etc, you get with round-trip-mode.

(originally posted on 2018-10-13 at 13:06:39)

[Anthon van der Neut]

Oh. Did not know about pure=True.

Turns out it solves an other problem I was having.

Thanks !

I guess we can close this issue, and perhaps talk about this is the documentation (if necessary)

(originally posted on 2018-10-13 at 13:52:26 by Dimitri Merejkowsky <dmerejkowsky@bitbucket>)

[Anthon van der Neut]

Well it needs to be solved. But I am probably not going to patch the libyaml much further, I rather start with code that also speeds up round-trip mode (libyaml strips the comments at a very low level).

I am glad I included the pure=True suggestion, I was just wondering why you were doing safe-loading (speed is of course much lower not using the C library).

(originally posted on 2018-10-13 at 17:03:56)