Sum a List of Numbers in Python

Summing elements in a list

You can sum numbers in a list simply with the sum() built-in:

sum(your_list)

It will sum as many number items as you have. Example:

my_list = range(10, 17)
my_list
[10, 11, 12, 13, 14, 15, 16]

sum(my_list)
91

For your specific case:

For your data convert the numbers into int first and then sum the numbers:

data = ['5', '4', '9']

sum(int(i) for i in data)
18

This will work for undefined number of elements in your list (as long as they are "numbers")

Thanks for @senderle's comment re conversion in case the data is in string format.

Sum a list of numbers until a number 0 is found

Iterate through the list and just add every time a non - zero number
and append a zero to the list.
when there is a 0 appearing just append the sum and make sum 0.
if the last element is 0 add zero to the last number or the
respective last number.
Just remove the first zero and return the list.

data = [1, 0, 0, 0, 1, 1, 1, 0, 2, 3, 1, 0, 0, 1, 1, 1, 0]

def calc(data):
    sum = 0
    new = []
    for i in range(len(data)):
        if data[i] == 0:
            new.append(sum)
            if i == len(data) - 1:
                new.append(0)
            sum = 0
        else:
            sum = sum = sum + data[i]
            new.append(0)
            if i == len(data) - 1:
                new.append(sum)
    if new[0] == 0:
        del new[0]
    return new

How can I sum a list of numbers?

Use this:

list_of_nums = []
loop = True
while loop == True:
    try: num = int(input("Enter Integer: "))
    except ValueError: num = "invalid"
    if num == "invalid": print("\nPlease Print A Valid Integer!\n");
    elif num != 0: list_of_nums.append(num)
    else: loop = False
print("\nSum of Inputed Integers: " + str(sum(list_of_nums)) + "\n")

Sum a list of numbers in string representation with leading whitespace

You could convert the strings to numbers already while reading the file, then just use sum on the list:

AtBats = []
with open(ff, "r") as file:
    next(file)
    while line := file.readline():
        AtBats.append(int(line.split(",")[-1]))

print(AtBats)
print(sum(AtBats))

Output:

[2, 6, 3, 5, 2]
18

Summing numbers from list with spaces in Python

There is several problems in your code

You don't use the iterated line and use infile.read() that reads the whole file at once, so there is only one iteration, and one value set in the array. You'd need someting like that
```
numbers = []
for line in infile:
    row_values = [int(i) for i in line.split()]
    numbers.extend(row_values)
```
you don't split each line, so you try to convert strings like '7 8' as one int that isn't possible
better use files with with statement, it autocloses them

The loop for reading is nice, but with your input format there is a better solution : str.split() without any parameter, it'll split on any amonut of whitespace, newlines included. So it can saparate each int, from each line at once

infile.read().split() # ['0', '1', '2', '4', '3', '8', '7', '8', '5', '6', '6', '7']
numbers = [int(i) for i in infile.read().split()]
# [0, 1, 2, 4, 3, 8, 7, 8, 5, 6, 6, 7]

Giving something like :

infileName = "test.txt"
with open(infileName, "r") as infile:
    numbers = [int(i) for i in infile.read().split()]

print(numbers)
total = sum(numbers)

outfilename = "out.txt"
with open(outfilename, "w") as outfile:
    outfile.write(str(total))

A very condensed version, with the files open at the same place would be

infileName, outfilename = "test.txt", "out.txt"
with open(infileName, "r") as infile, open(outfilename, "w") as outfile:
    outfile.write(str(sum(map(int, infile.read().split()))))

Prints a sub-list where the sum of its elements is the same as the sum of all the elements of the original list

If lst is your list of numbers then:

def get_sublist(lst):
    tot = sum(lst)
    for i in range(len(lst)):
        for j in range(i + 1, len(lst) + 1):
            sub_lst = lst[i:j]
            if sum(sub_lst) == tot:
                return sub_lst

sub_lst = get_sublist(lst)

This code generates every possible sublist, computes their sum and compares it with the sum of the entire list.

The complexity is not optimal, i.e. there are faster algorithms to solve this problem out there. For example, you don't need to compute the sum of the entire sublist every time you add a new element to it...