Source code for allensdk.brain_observatory.ecephys.stimulus_table.stimulus_parameter_extraction

import re
import ast


REPR_PARAMS_RE = re.compile(r"([a-z0-9]+=[^=]+)[,\)]", re.IGNORECASE)
REPR_CLASS_RE = re.compile(r"^(?P<class_name>[a-z0-9]+)\(.*\)$", re.IGNORECASE)
ARRAY_RE = re.compile(r"array\((?P<contents>\[.*\])\)")

DROP_PARAMS = (  # psychopy boilerplate, more or less
    "name",
    "autoLog",
    "autoDraw",
    "win",
)


def parse_stim_repr(
    stim_repr,
    drop_params=DROP_PARAMS,
    repr_params_re=REPR_PARAMS_RE,
    array_re=ARRAY_RE,
    raise_on_unrecognized=False,
):
    """ Read the string representation of a psychopy stimulus and extract
    stimulus parameters.

    Parameters
    ----------
    stim_repr : str
    drop_params : tuple
    repr_params_re : re.Pattern
    array_re : re.Pattern


    Returns
    -------
    dict :
        maps extracted parameter names to values

    """

    stim_params = extract_const_params_from_stim_repr(
        stim_repr, repr_params_re=repr_params_re, array_re=array_re
    )

    for drop_param in drop_params:
        if drop_param in stim_params:
            del stim_params[drop_param]

    return stim_params


# This is not currently in use by the stimulus_table module, but is a
# potentially handy utility
def extract_stim_class_from_repr(stim_repr, repr_class_re=REPR_CLASS_RE):
    match = repr_class_re.match(stim_repr)
    if match is not None and "class_name" in match.groupdict():
        return match["class_name"]


def extract_const_params_from_stim_repr(
    stim_repr, repr_params_re=REPR_PARAMS_RE, array_re=ARRAY_RE
):
    """Parameters which are not set as sweep_params in the stimulus script
    (usually because they are not varied during the course of the session) are
    not output in an easily machine-readable format. This function
    attempts to recover them by parsing the string repr of the stimulus.

    Parameters
    ----------
        stim_repr : str
            The repr of the camstim stimulus object. Served up per-stimulus
            in the stim pickle.
        repr_params_re : re.Pattern
            Extracts attributes as "="-seperated strings
        array_re : re.Pattern
            Extracts list reprs from numpy array reprs.

    Returns
    -------
    repr_params : dict
        dictionary of paramater keys and values extracted from the stim repr.
        Where possible, the values are converted to native Python types.

    """

    repr_params = {}

    for match in repr_params_re.findall(stim_repr):
        k, v = match.split("=")

        if k not in repr_params:

            m = array_re.match(v)
            if m is not None:
                v = m["contents"]

            try:
                v = ast.literal_eval(v)
            except ValueError:
                pass

            repr_params[k] = v

        else:
            raise KeyError(f"duplicate key: {k}")

    return repr_params