fastavro.json_write

json_writer(fo: IO, schema: Union[str, List[T], Dict[KT, VT]], records: Iterable[Any], *, write_union_type: bool = True, validator: bool = False, encoder=<class 'fastavro.io.json_encoder.AvroJSONEncoder'>, strict: bool = False, strict_allow_default: bool = False, disable_tuple_notation: bool = False) → None

Write records to fo (stream) according to schema

Parameters:

• fo – File-like object to write to
• schema – Writer schema
• records – Records to write. This is commonly a list of the dictionary representation of the records, but it can be any iterable
• write_union_type – Determine whether to write the union type in the json message. If this is set to False the output will be clear json. It may however not be decodable back to avro record by json_read.
• validator – If true, validation will be done on the records
• encoder – By default the standard AvroJSONEncoder will be used, but a custom one could be passed here
• strict – If set to True, an error will be raised if records do not contain exactly the same fields that the schema states
• strict_allow_default – If set to True, an error will be raised if records do not contain exactly the same fields that the schema states unless it is a missing field that has a default value in the schema
• disable_tuple_notation – If set to True, tuples will not be treated as a special case. Therefore, using a tuple to indicate the type of a record will not work

Example:

from fastavro import json_writer, parse_schema

schema = {
    'doc': 'A weather reading.',
    'name': 'Weather',
    'namespace': 'test',
    'type': 'record',
    'fields': [
        {'name': 'station', 'type': 'string'},
        {'name': 'time', 'type': 'long'},
        {'name': 'temp', 'type': 'int'},
    ],
}
parsed_schema = parse_schema(schema)

records = [
    {u'station': u'011990-99999', u'temp': 0, u'time': 1433269388},
    {u'station': u'011990-99999', u'temp': 22, u'time': 1433270389},
    {u'station': u'011990-99999', u'temp': -11, u'time': 1433273379},
    {u'station': u'012650-99999', u'temp': 111, u'time': 1433275478},
]

with open('some-file', 'w') as out:
    json_writer(out, parsed_schema, records)