Python: Calculate the sum of a list, after mapping each element to a value using a given function
Python List: Exercise - 250 with Solution
Write a Python program to calculate the sum of a list, after mapping each element to a value using the provided function.
- Use map() with fn to map each element to a value using the provided function.
- Use sum() to return the sum of the values.
Sample Solution:
Python Code:
def sum_by(lst, fn):
return sum(map(fn, lst))
print(sum_by([{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }], lambda v : v['n']))
Sample Output:
20
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Previous: Write a Python program to get the minimum value of a list, after mapping each element to a value using a given function.
Next: Write a Python program to initialize and fills a list with the specified value.
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Python: Tips of the Day
Given a predicate function, fn, and a prop string, this curried function will then take an object to inspect by calling the property and passing it to the predicate:
Example:
def tips_check_prop(fn, prop): return lambda obj: fn(obj[prop]) check_age = tips_check_prop(lambda x: x >= 25, 'age') user = {'name': 'Owen', 'age': 25} print(check_age(user))
Output:
True
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