Source code for jsonargparse.loaders_dumpers

"""Code related to loading and dumping."""

import inspect
import re
from typing import Any, Callable, Dict, Tuple, Type

import yaml

from ._common import load_value_mode, parent_parser
from .optionals import import_jsonnet, omegaconf_support
from .type_checking import ArgumentParser

__all__ = [

regex_curly_comma = re.compile(' *[{},] *')

class DefaultLoader(getattr(yaml, 'CSafeLoader', yaml.SafeLoader)):  # type: ignore

def remove_implicit_resolver(cls, tag_to_remove):
    if 'yaml_implicit_resolvers' not in cls.__dict__:
        cls.yaml_implicit_resolvers = cls.yaml_implicit_resolvers.copy()

    for first_letter, mappings in cls.yaml_implicit_resolvers.items():
        cls.yaml_implicit_resolvers[first_letter] = [
            (tag, regexp) for tag, regexp in mappings if tag != tag_to_remove

remove_implicit_resolver(DefaultLoader, ',2002:timestamp')
remove_implicit_resolver(DefaultLoader, ',2002:float')

    |\\.(?:nan|NaN|NAN))$''', re.X),

def yaml_load(stream):
    if stream.strip() == '-':
        value = stream
        value = yaml.load(stream, Loader=DefaultLoader)
    if isinstance(value, dict) and all(v is None for v in value.values()):
        keys = {k for k in regex_curly_comma.split(stream) if k}
        if len(keys) > 0 and keys == set(value.keys()):
            value = stream
    return value

def jsonnet_load(stream, path='', ext_vars=None):
    from .jsonnet import ActionJsonnet
    ext_vars, ext_codes = ActionJsonnet.split_ext_vars(ext_vars)
    _jsonnet = import_jsonnet('jsonnet_load')
        val = _jsonnet.evaluate_snippet(path, stream, ext_vars=ext_vars, ext_codes=ext_codes)
    except RuntimeError as ex:
            return yaml_load(stream)
        except pyyaml_exceptions:
            raise ValueError(str(ex)) from ex
    return yaml_load(val)

loaders: Dict[str, Callable] = {
    'yaml': yaml_load,
    'jsonnet': jsonnet_load,

pyyaml_exceptions = (yaml.YAMLError,)
jsonnet_exceptions = pyyaml_exceptions + (ValueError,)

loader_exceptions: Dict[str, Tuple[Type[Exception], ...]] = {
    'yaml': pyyaml_exceptions,
    'jsonnet': jsonnet_exceptions,

def get_load_value_mode() -> str:
    mode = load_value_mode.get()
    if mode is None:
        mode = parent_parser.get().parser_mode
    return mode

def get_loader_exceptions():
    return loader_exceptions[get_load_value_mode()]

def load_value(value: str, simple_types: bool = False, **kwargs):
    loader = loaders[get_load_value_mode()]
    if kwargs:
        params = set(list(inspect.signature(loader).parameters)[1:])
        kwargs = {k: v for k, v in kwargs.items() if k in params}
    loaded_value = loader(value, **kwargs)
    if not simple_types and isinstance(loaded_value, (int, float, bool, str)):
        loaded_value = value
    return loaded_value

dump_yaml_kwargs = {
    'default_flow_style': False,
    'allow_unicode': True,
    'sort_keys': False,

dump_json_kwargs = {
    'ensure_ascii': False,
    'sort_keys': False,

def yaml_dump(data):
    return yaml.safe_dump(data, **dump_yaml_kwargs)

def yaml_comments_dump(data, parser):
    dump = dumpers['yaml'](data)
    formatter = parser.formatter_class(parser.prog)
    return formatter.add_yaml_comments(dump)

def json_dump(data):
    import json
    return json.dumps(data, separators=(',', ':'), **dump_json_kwargs)

def json_indented_dump(data):
    import json
    return json.dumps(data, indent=2, **dump_json_kwargs)+'\n'

dumpers: Dict[str, Callable] = {
    'yaml': yaml_dump,
    'yaml_comments': yaml_comments_dump,
    'json': json_dump,
    'json_indented': json_indented_dump,
    'jsonnet': json_indented_dump,

comment_prefix: Dict[str,str] = {
    'yaml': '# ',
    'yaml_comments': '# ',
    'jsonnet': '// ',

def check_valid_dump_format(dump_format: str):
    if dump_format not in {'parser_mode'}.union(set(dumpers)):
        raise ValueError(f'Unknown output format "{dump_format}".')

def dump_using_format(parser: 'ArgumentParser', data: dict, dump_format: str) -> str:
    if dump_format == 'parser_mode':
        dump_format = parser.parser_mode if parser.parser_mode in dumpers else 'yaml'
    args = (data, parser) if dump_format == 'yaml_comments' else (data,)
    dump = dumpers[dump_format](*args)
    if parser.dump_header and comment_prefix.get(dump_format):
        prefix = comment_prefix[dump_format]
        header = '\n'.join(prefix + line for line in parser.dump_header)
        dump = f'{header}\n{dump}'
    return dump

[docs]def set_loader(mode: str, loader_fn: Callable[[str], Any], exceptions: Tuple[Type[Exception], ...] = pyyaml_exceptions): """Sets the value loader function to be used when parsing with a certain mode. The ``loader_fn`` function must accept as input a single str type parameter and return any of the basic types {str, bool, int, float, list, dict, None}. If this function is not based on PyYAML for things to work correctly the exceptions types that can be raised when parsing a value fails should be provided. Args: mode: The parser mode for which to set its loader function. Example: "yaml". loader_fn: The loader function to set. Example: ``yaml.safe_load``. exceptions: Exceptions that the loader can raise when load fails. Example: (yaml.parser.ParserError, yaml.scanner.ScannerError). """ loaders[mode] = loader_fn loader_exceptions[mode] = exceptions
[docs]def set_dumper(format_name: str, dumper_fn: Callable[[Any], str]): """Sets the dumping function for a given format name. Args: format_name: Name to use for dumping with this function. Example: "yaml_custom". dumper_fn: The dumper function to set. Example: ``yaml.safe_dump``. """ dumpers[format_name] = dumper_fn
def set_omegaconf_loader(): if omegaconf_support and 'omegaconf' not in loaders: from .optionals import get_omegaconf_loader set_loader('omegaconf', get_omegaconf_loader())