Source code for galaxy.util.yaml_util

from __future__ import absolute_import

import logging
import os
from collections import OrderedDict

import yaml
try:
    from yaml import CSafeLoader as SafeLoader
except ImportError:
    from yaml import SafeLoader
from yaml.constructor import ConstructorError


log = logging.getLogger(__name__)


[docs]class OrderedLoader(SafeLoader): # This class was pulled out of ordered_load() for the sake of # mocking __init__ in a unit test.
[docs] def __init__(self, stream): self._root = os.path.split(stream.name)[0] super(OrderedLoader, self).__init__(stream)
[docs] def include(self, node): filename = os.path.join(self._root, self.construct_scalar(node)) with open(filename, 'r') as f: return yaml.load(f, OrderedLoader)
[docs]def ordered_load(stream, merge_duplicate_keys=False): """ Parse the first YAML document in a stream and produce the corresponding Python object, using OrderedDicts instead of dicts. If merge_duplicate_keys is True, merge the values of duplicate mapping keys into a list, as the uWSGI "dumb" YAML parser would do. Otherwise, following YAML 1.2 specification which says that "each key is unique in the association", raise a ConstructionError exception. """ def construct_mapping(loader, node, deep=False): loader.flatten_mapping(node) mapping = OrderedDict() merged_duplicate = {} for key_node, value_node in node.value: key = loader.construct_object(key_node, deep=deep) value = loader.construct_object(value_node, deep=deep) if key in mapping: if not merge_duplicate_keys: raise ConstructorError("while constructing a mapping", node.start_mark, "found duplicated key (%s)" % key, key_node.start_mark) log.debug("Merging values for duplicate key '%s' into a list", key) if merged_duplicate.get(key): mapping[key].append(value) else: mapping[key] = [mapping[key], value] merged_duplicate[key] = True else: mapping[key] = value return mapping OrderedLoader.add_constructor( yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG, construct_mapping) OrderedLoader.add_constructor('!include', OrderedLoader.include) return yaml.load(stream, OrderedLoader)
[docs]def ordered_dump(data, stream=None, Dumper=yaml.Dumper, **kwds): class OrderedDumper(Dumper): pass def _dict_representer(dumper, data): return dumper.represent_mapping( yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG, list(data.items())) OrderedDumper.add_representer(OrderedDict, _dict_representer) return yaml.dump(data, stream, OrderedDumper, **kwds)