Chapter 8 - frequent_itemsets not defined

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2 print("num of required transactions = ", int(input_assoc_rules.shape[0]*support))
3 num_trans = input_assoc_rules.shape[0]*support
----> 4 itemsets = dict(frequent_itemsets(data_tran_uk_en, support))

NameError: name 'frequent_itemsets' is not defined