When it is required to find the sum of a list where the specific element is sum of first few elements, a method is defined, that takes list as parameter. It uses list comprehension to find the cumulative sum.
Below is the demonstration of the same −
Example
def cumulative_sum(my_list):
cumulative_list = []
my_length = len(my_list)
cumulative_list = [sum(my_list[0:x:1]) for x in range(0, my_length+1)]
return cumulative_list[1:]
my_list = [10, 20, 25, 30, 40, 50]
print("The list is :")
print(my_list)
print("The cumulative sum is :")
print (cumulative_sum(my_list))Output
The list is : [10, 20, 25, 30, 40, 50] The cumulative sum is : [10, 30, 55, 85, 125, 175]
Explanation
A method is defined, and a list is passed as a parameter to it.
An empty list is defined.
The length of the list is determined.
The list comprehension is used to iterate over the list.
It is converted to a list, and assigned to a variable.
The list from the second element to the last element is returned as output.
A list is defined outside the function and displayed on the console.
The method is called, and the list is passed as a parameter to it.
It is displayed as output on the console.