import argparse
import copy
import yaml
[docs]class NestedDictAction(argparse.Action):
"""Action class to append items to dict object.
Examples:
>>> parser = argparse.ArgumentParser()
>>> _ = parser.add_argument('--conf', action=NestedDictAction,
... default={'a': 4})
>>> parser.parse_args(['--conf', 'a=3', '--conf', 'c=4'])
Namespace(conf={'a': 3, 'c': 4})
>>> parser.parse_args(['--conf', 'c.d=4'])
Namespace(conf={'a': 4, 'c': {'d': 4}})
>>> parser.parse_args(['--conf', 'c.d=4', '--conf', 'c=2'])
Namespace(conf={'a': 4, 'c': 2})
>>> parser.parse_args(['--conf', '{d: 5, e: 9}'])
Namespace(conf={'d': 5, 'e': 9})
"""
_syntax = """Syntax:
{op} <key>=<yaml-string>
{op} <key>.<key2>=<yaml-string>
{op} <python-dict>
{op} <yaml-string>
e.g.
{op} a=4
{op} a.b={{c: true}}
{op} {{"c": True}}
{op} {{a: 34.5}}
"""
def __init__(
self,
option_strings,
dest,
nargs=None,
default=None,
choices=None,
required=False,
help=None,
metavar=None,
):
super().__init__(
option_strings=option_strings,
dest=dest,
nargs=nargs,
default=copy.deepcopy(default),
type=None,
choices=choices,
required=required,
help=help,
metavar=metavar,
)
def __call__(self, parser, namespace, values, option_strings=None):
# --{option} a.b=3 -> {'a': {'b': 3}}
if "=" in values:
indict = copy.deepcopy(getattr(namespace, self.dest, {}))
key, value = values.split("=", maxsplit=1)
if not value.strip() == "":
value = yaml.load(value, Loader=yaml.Loader)
if not isinstance(indict, dict):
indict = {}
keys = key.split(".")
d = indict
for idx, k in enumerate(keys):
if idx == len(keys) - 1:
d[k] = value
else:
if not isinstance(d.setdefault(k, {}), dict):
# Remove the existing value and recreates as empty dict
d[k] = {}
d = d[k]
# Update the value
setattr(namespace, self.dest, indict)
else:
try:
# At the first, try eval(), i.e. Python syntax dict.
# e.g. --{option} "{'a': 3}" -> {'a': 3}
# This is workaround for internal behaviour of configargparse.
value = eval(values, {}, {})
if not isinstance(value, dict):
syntax = self._syntax.format(op=option_strings)
mes = f"must be interpreted as dict: but got {values}\n{syntax}"
raise argparse.ArgumentTypeError(self, mes)
except Exception:
# and the second, try yaml.load
value = yaml.load(values, Loader=yaml.Loader)
if not isinstance(value, dict):
syntax = self._syntax.format(op=option_strings)
mes = f"must be interpreted as dict: but got {values}\n{syntax}"
raise argparse.ArgumentError(self, mes)
d = getattr(namespace, self.dest, None)
if isinstance(d, dict):
d.update(value)
else:
# Remove existing params, and overwrite
setattr(namespace, self.dest, value)