def isCommaSeparatedEmailList(field_data, all_data):
    """
    Checks that field_data is a string of e-mail addresses separated by commas.
    Blank field_data values will not throw a validation error, and whitespace
    is allowed around the commas.
    """
    for supposed_email in field_data.split(','):
        try:
            isValidEmail(supposed_email.strip(), '')
        except __HOLE__:
            raise ValidationError, gettext("Enter valid e-mail addresses separated by commas.")
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/core/validators.py/isCommaSeparatedEmailList