Source code for apache_beam.internal.gcp.json_value

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

"""JSON conversion utility functions."""

from __future__ import absolute_import

from apache_beam.options.value_provider import ValueProvider

# Protect against environments where apitools library is not available.
# pylint: disable=wrong-import-order, wrong-import-position
try:
  from apitools.base.py import extra_types
except ImportError:
  extra_types = None
# pylint: enable=wrong-import-order, wrong-import-position

try:              # Python 2
  unicode         # pylint: disable=unicode-builtin
  long            # pylint: disable=long-builtin
except NameError: # Python 3
  unicode = str
  long = int

_MAXINT64 = (1 << 63) - 1
_MININT64 = - (1 << 63)


[docs]def get_typed_value_descriptor(obj): """For internal use only; no backwards-compatibility guarantees. Converts a basic type into a @type/value dictionary. Args: obj: A basestring, bool, int, or float to be converted. Returns: A dictionary containing the keys ``@type`` and ``value`` with the value for the ``@type`` of appropriate type. Raises: ~exceptions.TypeError: if the Python object has a type that is not supported. """ if isinstance(obj, (str, unicode)): type_name = 'Text' elif isinstance(obj, bool): type_name = 'Boolean' elif isinstance(obj, int): type_name = 'Integer' elif isinstance(obj, float): type_name = 'Float' else: raise TypeError('Cannot get a type descriptor for %s.' % repr(obj)) return {'@type': 'http://schema.org/%s' % type_name, 'value': obj}
[docs]def to_json_value(obj, with_type=False): """For internal use only; no backwards-compatibility guarantees. Converts Python objects into extra_types.JsonValue objects. Args: obj: Python object to be converted. Can be :data:`None`. with_type: If true then the basic types (``string``, ``int``, ``float``, ``bool``) will be wrapped in ``@type:value`` dictionaries. Otherwise the straight value is encoded into a ``JsonValue``. Returns: A ``JsonValue`` object using ``JsonValue``, ``JsonArray`` and ``JsonObject`` types for the corresponding values, lists, or dictionaries. Raises: ~exceptions.TypeError: if the Python object contains a type that is not supported. The types supported are ``str``, ``bool``, ``list``, ``tuple``, ``dict``, and ``None``. The Dataflow API requires JsonValue(s) in many places, and it is quite convenient to be able to specify these hierarchical objects using Python syntax. """ if obj is None: return extra_types.JsonValue(is_null=True) elif isinstance(obj, (list, tuple)): return extra_types.JsonValue( array_value=extra_types.JsonArray( entries=[to_json_value(o, with_type=with_type) for o in obj])) elif isinstance(obj, dict): json_object = extra_types.JsonObject() for k, v in obj.items(): json_object.properties.append( extra_types.JsonObject.Property( key=k, value=to_json_value(v, with_type=with_type))) return extra_types.JsonValue(object_value=json_object) elif with_type: return to_json_value(get_typed_value_descriptor(obj), with_type=False) elif isinstance(obj, (str, unicode)): return extra_types.JsonValue(string_value=obj) elif isinstance(obj, bool): return extra_types.JsonValue(boolean_value=obj) elif isinstance(obj, (int, long)): if _MININT64 <= obj <= _MAXINT64: return extra_types.JsonValue(integer_value=obj) else: raise TypeError('Can not encode {} as a 64-bit integer'.format(obj)) elif isinstance(obj, float): return extra_types.JsonValue(double_value=obj) elif isinstance(obj, ValueProvider): if obj.is_accessible(): return to_json_value(obj.get()) return extra_types.JsonValue(is_null=True) else: raise TypeError('Cannot convert %s to a JSON value.' % repr(obj))
[docs]def from_json_value(v): """For internal use only; no backwards-compatibility guarantees. Converts ``extra_types.JsonValue`` objects into Python objects. Args: v: ``JsonValue`` object to be converted. Returns: A Python object structured as values, lists, and dictionaries corresponding to ``JsonValue``, ``JsonArray`` and ``JsonObject`` types. Raises: ~exceptions.TypeError: if the ``JsonValue`` object contains a type that is not supported. The types supported are ``str``, ``bool``, ``list``, ``dict``, and ``None``. The Dataflow API returns JsonValue(s) in many places and it is quite convenient to be able to convert these hierarchical objects to much simpler Python objects. """ if isinstance(v, extra_types.JsonValue): if v.string_value is not None: return v.string_value elif v.boolean_value is not None: return v.boolean_value elif v.integer_value is not None: return v.integer_value elif v.double_value is not None: return v.double_value elif v.array_value is not None: return from_json_value(v.array_value) elif v.object_value is not None: return from_json_value(v.object_value) elif v.is_null: return None elif isinstance(v, extra_types.JsonArray): return [from_json_value(e) for e in v.entries] elif isinstance(v, extra_types.JsonObject): return {p.key: from_json_value(p.value) for p in v.properties} raise TypeError('Cannot convert %s from a JSON value.' % repr(v))