def parse_by_prefix(input_string, prefix, end_char=[" "]):
    """searches through input_string until it finds the prefix. Returns
    everything in the string between prefix and the next instance of
    end_char"""

    start = input_string.find(prefix) + len(prefix)
    end = start

    while input_string[end] not in end_char:
        end += 1
    return input_string[start:end]