Yaml-5.1 fails with Numpy objects

[saimn]

#177 is similar, but was closed as fixed, so I'm opening a new issue.

In [1]: import yaml                                                                            

In [2]: import numpy                                                                           

In [3]: yaml.dump({'value': numpy.float64(1.234)})                                             
Out[3]: 'value: !!python/object/apply:numpy.core.multiarray.scalar\n- !!python/object/apply:numpy.dtype\n  args:\n  - f8\n  - 0\n  - 1\n  state: !!python/tuple\n  - 3\n  - <\n  - null\n  - null\n  - null\n  - -1\n  - -1\n  - 0\n- !!binary |\n  WDm0yHa+8z8=\n'

In [4]: yaml.full_load(yaml.dump({'value': numpy.float64(1.234)}))                             
---------------------------------------------------------------------------
ConstructorError                          Traceback (most recent call last)
<ipython-input-4-9a96300ff2cc> in <module>
----> 1 yaml.full_load(yaml.dump({'value': numpy.float64(1.234)}))

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/__init__.py in full_load(stream)
    140     unsafe on untrusted input.
    141     """
--> 142     return load(stream, FullLoader)
    143 
    144 def full_load_all(stream):

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/__init__.py in load(stream, Loader)
    112     loader = Loader(stream)
    113     try:
--> 114         return loader.get_single_data()
    115     finally:
    116         loader.dispose()

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in get_single_data(self)
     41         node = self.get_single_node()
     42         if node is not None:
---> 43             return self.construct_document(node)
     44         return None
     45 

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_document(self, node)
     50             self.state_generators = []
     51             for generator in state_generators:
---> 52                 for dummy in generator:
     53                     pass
     54         self.constructed_objects = {}

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_yaml_map(self, node)
    402         data = {}
    403         yield data
--> 404         value = self.construct_mapping(node)
    405         data.update(value)
    406 

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_mapping(self, node, deep)
    208         if isinstance(node, MappingNode):
    209             self.flatten_mapping(node)
--> 210         return super().construct_mapping(node, deep=deep)
    211 
    212     def construct_yaml_null(self, node):

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_mapping(self, node, deep)
    133                 raise ConstructorError("while constructing a mapping", node.start_mark,
    134                         "found unhashable key", key_node.start_mark)
--> 135             value = self.construct_object(value_node, deep=deep)
    136             mapping[key] = value
    137         return mapping

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_object(self, node, deep)
     92             data = constructor(self, node)
     93         else:
---> 94             data = constructor(self, tag_suffix, node)
     95         if isinstance(data, types.GeneratorType):
     96             generator = data

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in construct_python_object_apply(self, suffix, node, newobj)
    622             listitems = value.get('listitems', [])
    623             dictitems = value.get('dictitems', {})
--> 624         instance = self.make_python_instance(suffix, node, args, kwds, newobj)
    625         if state:
    626             self.set_python_instance_state(instance, state)

~/.pyenv/versions/3.7.2/lib/python3.7/site-packages/yaml/constructor.py in make_python_instance(self, suffix, node, args, kwds, newobj, unsafe)
    568             raise ConstructorError("while constructing a Python instance", node.start_mark,
    569                     "expected a class, but found %r" % type(cls),
--> 570                     node.start_mark)
    571         if newobj and isinstance(cls, type):
    572             return cls.__new__(cls, *args, **kwds)

ConstructorError: while constructing a Python instance
expected a class, but found <class 'builtin_function_or_method'>
  in "<unicode string>", line 1, column 8:
    value: !!python/object/apply:numpy.core ... 

[perlpunk]

See #265

Since this needs to call a function specified in the YAML, it is considered unsafe (when loading untrusted YAML), so you need to use unsafe_load in the future:

yaml.unsafe_load(y)
# or
yaml.load(y, Loader=yaml.UnsafeLoader)

Please reopen if this isn't working as expected, I tested it here and it works.

[saimn]

Oh thanks, indeed it works !