FACE Prep
faceprep.in › home › articles › sum of array elements in python: program to add array elements | face prep
Sum of Array Elements in Python: Add Array Elements | FACE Prep
March 3, 2025 - Use a for loop to collect array elements from the user. Append each element to the list. Use Python’s built-in sum() function to calculate the sum of all elements in the list.
University of Vermont
uvm.edu › ~cbcafier › cs1210 › book › 11_loops › loops_and_summation.html
Math and Python: loops and summation – Clayton Cafiero
We begin with a tuple of numeric values, t. Since the elements of t are all numeric, we can calculate their sum. First, we create a variable to hold the result of the sum. We call this, sum_.1 Then, we iterate over all the elements in t, and at each iteration of the loop, we add the value of ...
Sum of array in python - Stack Overflow
How could get the sum of an array in python, if array contains multiple variables ? How do we use sum function? Is the map function useful for that purpose ? Where as cardinalities are variables t... More on stackoverflow.com
How to cumulative sum over for loop?
First, don't overwrite list and sum, those are already existing functions. Second I am trying to take 1, and then add 4 Not exactly. You don't take 1 and then add 4. You take 0 and then add 1, then add 4, etc. So what you've forgotten is to "initialize" your sum as 0. Then you iteratively add all the values to that. l = [1, 4, 6, 3, 7, 5, 2, 8, 9] cumsum = 0 for i in l: cumsum += i If you don't first initialize a variable to 0, you have nothing to add that first value to. That's the piece you were missing. Edit: Minor improvement for clarity. More on reddit.com
20
12
December 17, 2021python - Get sum of numbers using a Function and For Loop - Stack Overflow
Communities for your favorite technologies. Explore all Collectives · Stack Overflow for Teams is now called Stack Internal. Bring the best of human thought and AI automation together at your work More on stackoverflow.com
Summing up elements in a list in python using a for loop - Stack Overflow
While working on a program that creates bars out of sets of numbers in a list, I found that adding up items in my list doesn't work. I thought the best way to do this is just to make a for loop. H... More on stackoverflow.com
Videos
Django Central
djangocentral.com › sum-of-elements-of-an-array-or-list
Python Program To Find The Sum Of Elements Of An Array or List
Make a Python Function which takes ... to store the sum and initializing it to 0. Next, the for loop iterates over each element of the array / list and storing their sum in the total variable, at last function returns the total....
DEV Community
dev.to › askyt › python-program-to-find-the-sum-of-an-array-bci
Python Program to Find the Sum of an Array - DEV Community
January 31, 2025 - # Function to calculate sum using a loop def sum_array(arr): total = 0 for num in arr: total += num return total # Example usage arr = [5, 8, 12, 20] print("Sum of the array is", sum_array(arr))
PrepBytes
prepbytes.com › home › python › python program to find sum of array
Python Program to Find Sum of Array
June 18, 2024 - Q3: How can you find the sum of elements in an array? You can find the sum of elements in an array using a loop to iterate through the elements and accumulate the sum or by using Python’s built-in sum() function.
w3resource
w3resource.com › python-exercises › numpy › numpy-cumulative-sum-of-large-array-using-for-loop-and-optimization.php
NumPy - Cumulative sum of large array using For loop and optimization
September 1, 2025 - Learn how to calculate the cumulative sum of a large 1D NumPy array using a for loop and optimize it with NumPy's cumsum() function. Follow our step-by-step guide for efficient array operations.
Tutorial Gateway
tutorialgateway.org › python-program-to-find-sum-of-numpy-array
Python Program to Find Sum of Numpy Array
January 24, 2025 - Within this for loop, we are adding each item to the total (total = total + sumArr[I]). import numpy as np sumArr = np.array([10, 60, 30, 40, 70, 95]) total = 0 for i in range(len(sumArr)): total = total + sumArr[i] print("The Sum of Total Array ...
GeeksforGeeks
geeksforgeeks.org › sum-function-python
sum() function in Python - GeeksforGeeks
January 2, 2025 - ... In this, the code first defines a list of numbers. It then initializes a variable called total to 0. The code then iterates through the list using a for loop, and for each number in the list, it adds that number to the total variable.
GeeksforGeeks
geeksforgeeks.org › python › python-program-to-find-sum-of-array
Python Program to Find Sum of Array - GeeksforGeeks
November 4, 2025 - Explanation: reduce() applies a function cumulatively to items of the iterable, combining them into a single result (here it repeatedly adds pairs). Iterating through the array and adding each element to the sum variable and finally displaying ...
CodeRivers
coderivers.org › blog › array-sum-python
Mastering Array Sum in Python: A Comprehensive Guide - CodeRivers
February 22, 2026 - Here's how it works: my_list = [1, 2, 3, 4, 5] sum_value = 0 for num in my_list: sum_value += num print(sum_value) In this code, we initialize a variable sum_value to 0. Then, we iterate through each element in the my_list using a for loop. For each element, we add it to the sum_value.
Reddit
reddit.com › r/learnpython › how to cumulative sum over for loop?
r/learnpython on Reddit: How to cumulative sum over for loop?
December 17, 2021 -
Hello, so I am trying to understand how to sum values through a for loop within python so that I start with a value, and then add to it, and then add the next value to that, and then add the next value to that, and so on, going through all values in my list/folder. I think this would be referred to as a "cumulative sum". So let's say I have a list of numbers:
list = [1,4,6,3,7,5,2,8,9]
I want to iterate over each value in this list and add all values to the previous like so:
for value in list:
1 + value
sum = 1 + value
print(sum)or something like that? I tried this, and it just adds one to each value in the list, when I want a single final cumulative sum produced. I am really confused about if my logic is correct there. Is this how I would carry out this cumulative sum operation? I am trying to take 1, and then add 4, and then add 6 to that, and then add 3 to that sum, and then add 7 to that sum, and so on. I realize one could also just add all of these values at once, but I am trying to understand how to do this with a for loop. Thanks!
Top answer 1 of 10
20
First, don't overwrite list and sum, those are already existing functions. Second I am trying to take 1, and then add 4 Not exactly. You don't take 1 and then add 4. You take 0 and then add 1, then add 4, etc. So what you've forgotten is to "initialize" your sum as 0. Then you iteratively add all the values to that. l = [1, 4, 6, 3, 7, 5, 2, 8, 9] cumsum = 0 for i in l: cumsum += i If you don't first initialize a variable to 0, you have nothing to add that first value to. That's the piece you were missing. Edit: Minor improvement for clarity.
2 of 10
8
How would you do it in real life? (not on a computer) If a friend was going to shout these numbers at you, one at a time, what would you do? 1......4......6......3....etc? 1 is easy. The sum is 1. What happens when the friend shouts 4? Do you remember both the 1 and the 4? No, add them. 5. Now what happens when the friend shouts 6? As long as you remember the previous sum, 5, you can add 6 on to it to get 11. With this mind, look at your loop, specifically line 3: sum = You want that to be: make the sum equal whatever it equaled before, plus the new value that was just "shouted" as part of the loop.
Top answer 1 of 3
1
By for loop
def sumAll(n):
sum_all = 0
for i in range(1, n+1):
sum_all = sum_all + i
return sum_all
number = int(raw_input("Please enter a number: \n"))
print ("The answer is: ") + str(sumAll(number))
Output:
Please enter a number:
10
The answer is: 55
You can also use list Comprehension:
print sum([i for i in range(number+1)])
Output:
55
You can also use a mathematical series formula:
def sumAll(n):
return n * (n + 1) / 2
2 of 3
0
you can even do it without a loop:
def sumAll(n):
return sum(range(1,n+1))
print(sumAll(10)) # -> 55
if you insist on using a loop:
def sumAll(n):
s = 0
for i in range(1,n+1):
s += i
return s
but the mathematical solution is simply:
def sumAll(n):
return n * (n + 1) / 2
# in python 3:
# return n * (n + 1) // 2
(there are n elements with an average value of (n+1)/2; this will always be an integer since either n or n+1 is even; the proof by induction is often the first example when math students learn about induction...).
Real Python
realpython.com › python-sum-function
Python's sum(): The Pythonic Way to Sum Values – Real Python
July 21, 2023 - In this step-by-step tutorial, you'll learn how to use Python's sum() function to add numeric values together. You also learn how to concatenate sequences, such as lists and tuples, using sum().
Bobby Hadz
bobbyhadz.com › blog › python-sum-in-for-loop
How to sum in a For or a While Loop in Python | bobbyhadz
The map() function passes each string to the int() class and converts it to an integer. ... Iterate for as long as the number is greater than 0. On each iteration, decrement the number by 1. On each iteration, increment the total by the number.
Sololearn
sololearn.com › en › Discuss › 2922107 › given-a-list-of-numbers-calculate-their-sum-using-a-for-loop-output-the-sum-after-the-loop
Given a list of numbers, calculate their sum using a for loop. Output the sum after the loop | Sololearn: Learn to code for FREE!
x = [42, 8, 7, 1, 0, 124, 8897, 555, 3, 67, 99] sum = 0 for n in x: sum+=n print(sum)
W3Schools
w3schools.com › python › ref_func_sum.asp
Python sum() Function
Python Examples Python Compiler ... Python Interview Q&A Python Bootcamp Python Training ... The sum() function returns a number, the sum of all items in an iterable....
Python Guides
pythonguides.com › sum-elements-in-list-in-python-using-for-loop
How To Sum Elements In A List In Python
June 3, 2024 - As we have seen, this can be done in many different ways, depending on the situation and aesthetic preferences. Be it through a very simple for loop, using the sum() function, the perfect, concise way of using list comprehensions, or the more ...
Top answer 1 of 4
7
>>> phonelist = [[12,14,16,17,18],[16,23,54,64,32]]
>>> [sum(li) for li in phonelist]
[77, 189]
>>> sum([sum(li) for li in phonelist])
266
or:
>>> sum(sum(li) for li in phonelist) # generator expression...
266
If you are trying to create individual categories, you can use a dict:
data={'Bar {}'.format(i):sum(li) for i, li in enumerate(phonelist, 1)}
data['Total']=sum(data.values())
print data
{'Bar 2': 189, 'Bar 1': 77, 'Total': 266}
Then if you want to produce a simple bar graph:
for bar in sorted(data.keys()):
print '{}: {}'.format(bar, int(round(25.0*data[bar]/data['Total']))*'*')
Prints:
Bar 1: *******
Bar 2: ******************
Total: *************************
2 of 4
2
len(phonelist[0]) is an int, so you can't loop over it. You can change that to
for x in phonelist[0]:
This way x will take on each value of phonelist[0].