import re


def seq_get_vp_region(seq):
    """
    Get viewpoint (uppercase region) from a sequence.

    >>> seq = "acguAACCGGacgu"
    >>> seq_get_vp_region(seq)
    'AACCGG'

    """
    assert seq, "seq empty"
    vp_seq = False
    m = re.search("[acgun]*([ACGUN]+)", seq)
    if m:
        vp_seq = m.group(1)
    return vp_seq