# Introduction :

In this python programming tutorial, we will learn how to find the *sum* of all *odd numbers* and *even numbers* in a *list*. The program will ask the user to enter the *size* of the list first. Then, it will ask each number to add to the list one by one. Finally, the program will calculate and print out the *sum of all odd numbers and even numbers* in the list.

## Algorithm :

We will use the below algorithm to solve this problem :

- Ask the user to enter the
*list size*. - Take all inputs of the list from the user
*one by one*. - Now, calculate the
*sum of all odd numbers and even numbers*in the list. - Finally, print out the
*sum*of*odd*numbers and*even*numbers.

### Python program :

```
# 1
size = int(input("Enter the size of the list : "))
# 2
sum_odd = 0
sum_even = 0
# 3
int_list = []
# 4
for i in range(size):
# 5
n = int(input("Enter element {} : ".format(i+1)))
int_list.append(n)
# 6
for i in range(size):
# 7
if(int_list[i] % 2 == 0):
sum_even += int_list[i]
else:
sum_odd += int_list[i]
# 8
print("Sum of odd numbers : {} ".format(sum_odd))
print("Sum of even numbers : {} ".format(sum_even))
```

### Explanation :

*The commented numbers in the above program denote the step numbers below:*

- Ask the user to enter the
*size*of the list. Read it and store it in the*size*variable. - Create two variables
*sum_odd*and*sum_even*to hold the sum of*odd*and*even*numbers in the list. - Create one empty list
*int_list*. - Run one
*for loop*in the range of the user-provided*size*.If the size is*4*this loop will run for*4 times starting i = 0 to i = 3*. - On each iteration of the loop, ask the user to enter the
*element*for the list. Read each element and append it to the list*int_list*. - Run one more loop similarly in the same range. This loop is for finding out the
*sum*of*odd*and*even*numbers in the*list*. - On each iteration, check if the current iterating element of the list is
*even or odd*. If*even*, add it to the variable*sum_even*and if odd, add it to*sum_odd*. - Finally, print out the
*sum*of all*odd*and*even*numbers to the user.

### Sample Output :

```
Enter the size of the list : 3
Enter element 1 : 1
Enter element 2 : 2
Enter element 3 : 3
Sum of odd numbers : 4
Sum of even numbers : 2
Enter the size of the list : 5
Enter element 1 : 12
Enter element 2 : 23
Enter element 3 : 34
Enter element 4 : 22
Enter element 5 : 1
Sum of odd numbers : 24
Sum of even numbers : 68
```

### Conclusion :

As you have in the example, we can easily calculate the *sum* of *odd* and *even* numbers in a list in python. Try to run the example above and drop one comment below if you have any queries.