if readdata: data = np.fromstring(" -".join(line.strip().split("-")), sep=" ") * exponent
This line doesn't parse case when all number places in value are used (there's 5 places per value in data in IONEX file) correctly. It's better to split them by 5 characters, not by space.
Using just datetime.datetime in parsing data in IONEX header also is not enough: sometimes they use 24th hour of current day instead of 0 hour of next day, what leads to datetime error. So this case should be handled separately.
if readdata: data = np.fromstring(" -".join(line.strip().split("-")), sep=" ") * exponentThis line doesn't parse case when all number places in value are used (there's 5 places per value in data in IONEX file) correctly. It's better to split them by 5 characters, not by space.datetime.datetimein parsing data in IONEX header also is not enough: sometimes they use 24th hour of current day instead of 0 hour of next day, what leads todatetimeerror. So this case should be handled separately.