如何在没有空格的数字串中添加每个数字

Question

Im currently trying to take a sequence of numbers in a string input, and then convert those numbers into a total to print. In concept this should be easy, but I'm having trouble figuring it out. I've searched Stack but could not find a solution that fits my current problem.

This is my current progress:

def main():
numbers= input("Enter a sequence of numbers with no spaces:")
numbers= list(numbers)
total= ""
for i in numbers:
    total= total + i

print(total)

main()

My logic is to break the sequence of numbers into a list, then add the numbers in a loop, to then produce the total. Unfortunately this only returns the original string, so I decided to put:

for i in numbers:

i= eval(i)
total= total + i

and

for i in numbers:

i= int(i)
total= total + i

This returns an error stating that i needs to be a string, but this will only lead to another concatenation.

Does anyone know how to produce what I'm looking for? ie "1234" = 10.

Answer 1

The string itself is an iterable, so you can iterate over it and convert each character to an int and then use sum to add them.

>>> numbers= input("Enter a sequence of numbers with no spaces:")
Enter a sequence of numbers with no spaces:1234567
>>> sum([int(i) for i in numbers])
28

or lose the outer [] to make it a generator expression. It will work either way, however for a small input like this arguably the generator overhead might exceed its benefits in terms of memory usage.

Answer 2

There's no need to turn the string into a list, since it's already an iterable. Instead, just do something like this:

numbers = input(‘Enter numbers: ‘)
total = 0

for char in numbers:
    total += int(char)

print(total)

This goes through each character in the string, turns it into an integer, and adds it to the total.

Answer 3

Just to add one more answer here. If your string that you are accepting is comma seperated, then here is a one liner if it is python 2.7

 sequence = map(int, input().split(','))

else for python3,

sequence = list(map(int, input().split(',')))

I hope it adds something to already given answers.