Exception in yaml.dump() with Dumper and default_style=True, but not with CDumper

[sylvain]

Hello,

I meet a reproducible Exception when dumping a python dictionary with default_style=True. This occurs when Dumper=yaml.Dumper, but not with the CDumper.

My setup:

python-yaml, version: 3.09-5 python2.6.6, libyaml-0-2

A simple script to reproduce this exception:

---

#!/usr/bin/python

import yaml

str_in = """ test:

a: b

"""

d = yaml.load(str_in, Loader=yaml.Loader)

print yaml.dump(d, Dumper=yaml.CDumper) print yaml.dump(d, Dumper=yaml.CDumper, default_style=True) print yaml.dump(d, Dumper=yaml.Dumper) # This line causes an exception print yaml.dump(d, Dumper=yaml.Dumper, default_style=True)

---

The exception is as follows:

Traceback (most recent call last):

File "./yamlerr.py", line 15, in <module>

print yaml.dump(d, Dumper=yaml.Dumper, default_style=True)

File "/usr/lib/python2.6/dist-packages/yaml/init.py", line 175, in dump

return dump_all([data], stream, Dumper=Dumper, kwds)

File "/usr/lib/python2.6/dist-packages/yaml/init.py", line 165, in dump_all

dumper.represent(data)

File "/usr/lib/python2.6/dist-packages/yaml/representer.py", line 34, in represent

self.serialize(node)

File "/usr/lib/python2.6/dist-packages/yaml/serializer.py", line 54, in serialize

self.serialize_node(node, None, None)

File "/usr/lib/python2.6/dist-packages/yaml/serializer.py", line 108, in serialize_node

self.serialize_node(value, node, key)

File "/usr/lib/python2.6/dist-packages/yaml/serializer.py", line 107, in serialize_node

self.serialize_node(key, node, None)

File "/usr/lib/python2.6/dist-packages/yaml/serializer.py", line 90, in serialize_node

style=node.style))

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 110, in emit

self.state()

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 389, in expect_first_block_mapping_key

return self.expect_block_mapping_key(first=True)

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 399, in expect_block_mapping_key

self.expect_node(mapping=True, simple_key=True)

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 238, in expect_node

self.process_tag()

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 469, in process_tag

self.style = self.choose_scalar_style()

File "/usr/lib/python2.6/dist-packages/yaml/emitter.py", line 501, in choose_scalar_style

if self.event.style and self.event.style in '|>':

TypeError?: 'in <string>' requires string as left operand, not bool

---

Thanks in advance for your feedback.

[anonymous]

This scenario does not seem valid, as default_style requires to be string, not a boolean.

You might use default_flow_style rather than default_flow_style. However, the problem might be that the CDumper does not seem to honor that parameter.