def common_prefix_length(seq_a, seq_b):
    """
    Return the length of the common prefix between two sequences.

    Parameters
    ----------
    seq_a : iter
        An iterable holding the first sequence.
    seq_b : iter
        An iterable holding the second sequence.

    Returns
    -------
    length: int
        The length of the common prefix between `seq_a` and `seq_b`.

    Examples
    --------

    >>> import dafsa
    >>> dafsa.utils.common_prefix_length("abcde", "abcDE")
    3
    >>> dafsa.utils.common_prefix_length("abcde", "ABCDE")
    0
    """
    common_prefix_len = 0
    for i in range(min(len(seq_a), len(seq_b))):
        if seq_a[i] != seq_b[i]:
            break
        common_prefix_len += 1
    return common_prefix_len
