Python provides 3 useful global functions we can use to work with collections:
Tip: sometimes list comprehensions make more sense and are generally considered more pythonic
reduce() is used to calculate a value out of a sequence, like a list.
For example suppose you have a list of expenses, stored as tuples, and you want to calculate the sum of a property property in each tuple, in this case the cost of each expense:
expenses = [ ('Dinner', 80), ('Car repair', 120) ]
You could iterate with a loop over them:
sum = 0 for expense in expenses: sum += expense print(sum) # 200
Or, you can use
reduce() to reduce the list to a single value:
from functools import reduce print(reduce(lambda a, b: a + b, expenses)) # 200
reduce()is not available by default like
filter(). You need to import it from the standard library module
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