# 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.