#229 ruamel.yaml round trip loader messes up floats that start with a '.'

[Anthon van der Neut]

#!python

ruamel.yaml.round_trip_dump(ruamel.yaml.round_trip_load('.5'))
> "!!float '00'\n"
ruamel.yaml.round_trip_dump(ruamel.yaml.round_trip_load('.55'))
> '0.6\n...\n'

Looks like it's a problem with how the properties are interpreted on output:

#!python

obj = ruamel.yaml.round_trip_load("""

- .5
- 0.5
""")
obj[0].__dict__
> {'_m_lead0': 0, '_underscore': None, '_e_sign': None, '_exp': None, '_width': 2, '_e_width': None, '_prec': 0, '_m_sign': False}
obj[1].__dict__
> {'_m_lead0': 1, '_underscore': None, '_e_sign': None, '_exp': None, '_width': 3, '_e_width': None, '_prec': 1, '_m_sign': False}

obj[0]._width = 3

ruamel.yaml.round_trip_dump(obj)
> - 0.5
> - 0.5

I can't figure out how to make it output '.5', but I don't really care about that. I'd be alright with it adding a leading 0.

My workaround is:

#!python
def represent_float(self, value):
  if value._prec == 0:
    value._width += 1
    value._prec += 1
  return ruamel.yaml.representer.RoundTripRepresenter.represent_scalar_float(self, value)

ruamel.yaml.RoundTripRepresenter.add_representer(ruamel.yaml.scalarfloat.ScalarFloat, represent_float)

which adds a leading 0 when necessary.

(originally posted on 2018-08-30 at 17:43:44 by Harrison Gregg <HarrisonGregg@bitbucket>)

[Anthon van der Neut]

None
(originally posted on 2018-08-30 at 18:05:48 by Harrison Gregg <HarrisonGregg@bitbucket>)

[Anthon van der Neut]

Thanks for reporting and the analysis. Of course there was no test for this format...

Python's string method .format() doesn't support floats that start with a dot which makes things a little more difficult

(originally posted on 2018-08-30 at 18:41:49)

[Anthon van der Neut]

add failing test re #229

→ <<cset d9b4821ef1d6="">></cset>

(originally posted on 2018-08-30 at 18:42:10)

[Anthon van der Neut]

• status set to resolved

fix issue #229 enable round-trip of floats without number before the dot

[ .5, -.5, +.5 ] should work

When this change indeed resolves your problem, please Close this issue.
(You can do so using the WorkFlow pull-down (close to the top right of this page))

→ <<cset 31238c6c8ff7="">></cset>

(originally posted on 2018-08-30 at 19:00:24)

[Anthon van der Neut]

Thanks for the quick turnaround!

(originally posted on 2018-08-31 at 16:23:53 by Harrison Gregg <HarrisonGregg@bitbucket>)

[Anthon van der Neut]

• status set to closed

Fixed!

(originally posted on 2018-08-31 at 16:24:07 by Harrison Gregg <HarrisonGregg@bitbucket>)

[Anthon van der Neut]

Issue #257 was marked as a duplicate of this issue.

(originally posted on 2018-11-06 at 18:34:06)