"""Contain logic for checking standard error files"""
import re

from .errors import InvalidCellValue

def valid_value(val):
    if re.search("^[0-9]+\.[0-9]{6,}$", val):
        return float(val)
    raise InvalidCellValue(
        f"Invalid value '{val}'.\n"
        "Expected string representing a number with at least six decimal "
        "places.")