def is_seq(x, step=1):
    """Checks if the elements in a list-like object are increasing by step

    Parameters
    ----------
    x: list-like
    step

    Returns
    -------
    True if elements increase by step, else false and the index at which the condition is violated.

    """
    for i in range(1, len(x)):
        if not x[i] == (x[i - 1] + step):
            print('Not seq at: ', i)
            return False
    return True