col1 = df.col1.values.repeat([len(c) for c in c2.tolist()])
col2 = list(cytoolz.concat(c2))
np.stack([col1, col2]).ravel('F')
array(['High street', 'qwe.723', 'High street', 'qwe.2', 'High street',
    'qwe.17', 'High street', 'qwe.1000', 'High street', 'qwe.23',
    'Must street', 'qwe.34', 'Must street', 'qwe.17', 'Must street',
    'qwe.1000', 'Must street', 'qwe.23'], dtype=object)
looping through multiple values in a column