import re


def _split_ver(ver_str):
    """Parse the given version into a tuple of "significant" parts.
   
        >>> _split_ver("4.1.0")
        ('4', '1', '0')
        >>> _split_ver("1.3a2")
        ('1', '3', 'a', '2')
    """
    bits = [b for b in re.split("(\.|[a-z])", ver_str) if b != '.']
    return tuple(bits)