from typing import Iterable


def make_var_name(label):
    """ Generate correct variable name from text label (or iterable array of labels)

    >>> make_var_name("Test text ji*((i_i")
    'var_testtextjiii'

    >>> make_var_name(['Haul', 'Date', 'Operation'])
    ['var_haul', 'var_date', 'var_operation']
    """
    if isinstance(label, str):
        return "var_" + "".join(c.lower() for c in label if c.isalnum())
    elif isinstance(label, Iterable):
        labels = label
        return [make_var_name(label) for label in labels]