Like this, Python’s dict() function is perfectly designed for converting a list of tuples, which is what you have:
>>> string = [('limited', 1), ('all', 16), ('concept', 1), ('secondly', 1)]
>>> my_dict = dict(string)
>>> my_dict
{'all': 16, 'secondly': 1, 'concept': 1, 'limited': 1}