def __init__(self, start_prices=None, freq='minute', start=None,
                 end=None, drift=0.1, sd=0.1, calendar=calendar_nyse):
        # Hash_value for downstream sorting.
        self.arg_string = hash_args(start_prices, freq, start, end,
                                    calendar.__name__)

        if freq not in self.VALID_FREQS:
            raise ValueError('%s not in %s' % (freq, self.VALID_FREQS))

        self.freq = freq
        if start_prices is None:
            self.start_prices = {0: 100,
                                 1: 500}
        else:
            self.start_prices = start_prices

        self.calendar = calendar
        if start is None:
            self.start = calendar.start
        else:
            self.start = start
        if end is None:
            self.end = calendar.end_base
        else:
            self.end = end

        self.drift = drift
        self.sd = sd

        self.sids = self.start_prices.keys()

        self.open_and_closes = \
            calendar.open_and_closes[self.start:self.end]

        self._raw_data = None
Parse a configuration file at `file_path` and store it.  This function
dataset/ETHPy150Open quantopian/zipline/zipline/sources/simulated.py/RandomWalkSource.__init__--crossover with--dataset/ETHPy150Open datafolklabs/cement/cement/core/config.py/CementConfigHandler._parse_file