microsoft/qlib · error · ValueError

Get Unexpected arguments {kwargs}

Error message

Get Unexpected arguments {kwargs}

What it means

The Exchange constructor accepts only one extra keyword beyond its named parameters: 'trade_unit', which it pops from kwargs. After that pop, any remaining entry in kwargs is a typo'd or unsupported parameter, and the constructor raises ValueError listing the leftovers. This is a fail-fast guard against silently ignored misspelled arguments.

Source

Thrown at qlib/backtest/exchange.py:137

                                                $close is for calculating the total value at end of each day.
                                            Optional fields:
                                                $volume is only necessary when we limit the trade amount or calculate
                                                PA(vwap) indicator
                                                $vwap is only necessary when we use the $vwap price as the deal price
                                                $factor is for rounding to the trading unit
                                                limit_sell will be set to False by default (False indicates we can sell
                                                this target on this day).
                                                limit_buy will be set to False by default (False indicates we can buy
                                                this target on this day).
                                    index: MultipleIndex(instrument, pd.Datetime)
        """
        self.freq = freq
        self.start_time = start_time
        self.end_time = end_time

        self.trade_unit = kwargs.pop("trade_unit", C.trade_unit)
        if len(kwargs) > 0:
            raise ValueError(f"Get Unexpected arguments {kwargs}")

        if limit_threshold is None:
            limit_threshold = C.limit_threshold
        if deal_price is None:
            deal_price = C.deal_price

        # we have some verbose information here. So logging is enabled
        self.logger = get_module_logger("online operator")

        # TODO: the quote, trade_dates, codes are not necessary.
        # It is just for performance consideration.
        self.limit_type = self._get_limit_type(limit_threshold)
        if limit_threshold is None:
            if C.region in [REG_CN, REG_TW]:
                self.logger.warning(f"limit_threshold not set. The stocks hit the limit may be bought/sold")
        elif self.limit_type == self.LT_FLT and abs(cast(float, limit_threshold)) > 0.1:
            if C.region in [REG_CN, REG_TW]:
                self.logger.warning(f"limit_threshold may not be set to a reasonable value")

View on GitHub (pinned to 79633dd950)

Solutions

1. Inspect the error message: the {kwargs} dict names exactly which keys are unrecognized; fix or remove those keys
2. If building Exchange from a config dict, filter keys against the constructor signature (inspect.signature) before the call
3. Check the current Exchange.__init__ signature in your installed qlib version for renamed parameters (e.g. trade_unit is the only accepted extra kwarg)

Example fix

# before
exch = Exchange(freq='day', trade_units=100)  # 'trade_units' -> ValueError
# after
exch = Exchange(freq='day', trade_unit=100)

import inspect
sig = inspect.signature(Exchange.__init__)
allowed = set(sig.parameters) | {'trade_unit'}
unknown = {k for k in cfg if k not in allowed and k != 'self'}
assert not unknown, f"Unknown Exchange kwargs: {unknown}"
exch = Exchange(**cfg)

When it happens

Trigger: Instantiating Exchange(...) with unknown keywords, e.g. Exchange(volume_threshold=...) when it is a named param misspelled, or passing removed/renamed options like Exchange(trade_units=100) or dealer-style kwargs; also forwarding **config dicts that contain stale keys.

Common situations: Version upgrades where Exchange parameters were renamed or removed; config files (yaml/json) whose keys are dumped into Exchange(**cfg); copy-pasted example code from an older qlib README.

Related errors

• This type of input {rtype} is not supported
• direction {direction} is not supported!
• weight_position is {}, weight_position is not in the range o
• {limit[0]} is not supported
• This type of input is not supported

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/429b44deb73203e9. Report an issue: GitHub.