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Python Program to find Sum of Even and Odd Numbers in a List

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Write a Python Program to find Sum of Even and Odd Numbers in a List using For Loop, While Loop, and Functions with practical example.

Before you start, please refer List article to understand everything about Lists.

Python Program to find Sum of Even and Odd Numbers in a List using For Loop

In this python program, we are using For Loop to iterate each and every element in a given List. Inside the loop we are using If statement to check and find Sum of Even and odd numbers.

# Python Program to find Sum of Even and Odd Numbers in a List

NumList = []
Even_Sum = 0
Odd_Sum = 0

Number = int(input("Please enter the Total Number of List Elements: "))
for i in range(1, Number + 1):
    value = int(input("Please enter the Value of %d Element : " %i))
    NumList.append(value)

for j in range(Number):
    if(NumList[j] % 2 == 0):
        Even_Sum = Even_Sum + NumList[j]
    else:
        Odd_Sum = Odd_Sum + NumList[j]

print("\nThe Sum of Even Numbers in this List =  ", Even_Sum)
print("The Sum of Odd Numbers in this List =  ", Odd_Sum)

OUTPUT

Python Program to find Sum of Even and Odd Numbers in a List 1

ANALYSIS
User entered items = [2, 3, 4, 5], Even_Sum = 0, Odd_Sum = 0

For Loop – First Iteration: for 0 in range(0, 4)
The condition is True so, compiler will enter into the If Statement
if(NumList[0] % 2 == 0) => if(2 % 2 == 0) – Condition is True
Even_Sum = Even_Sum + NumList[0]  => 0 + 2 = 2

Second Iteration: for 1 in range(0, 4) – Condition is True
if(NumList[1] % 2 == 0) => if(3 % 2 == 0) – Condition is False
Compiler will enter into the Else block.
Odd_Sum = Odd_Sum + NumList[1] => 0 + 3 = 3

Third Iteration: for 2 in range(0, 4) – Condition is True
if(NumList[2] % 2 == 0) => if(4 % 2 == 0) – Condition is True
Even_Sum = 2 + 4 = 6

Fourth Iteration: for 3 in range(0, 4) – Condition is True
if(5 % 2 == 0) – Condition is False
Compiler will enter into Else block.
Odd_Sum = 3 + 5 = 8

Fifth Iteration: for 4 in range(4) – Condition is False
So compiler will exit from For Loop

Python Program to find Sum of Even and Odd Numbers in a List using While loop

This program for calculating sum of even and odd numbers is same as above. We just replaced the For Loop with While loop.

# Python Program to find Sum of Even and Odd Numbers in a List

NumList = []
Even_Sum = 0
Odd_Sum = 0
j = 0

Number = int(input("Please enter the Total Number of List Elements: "))
for i in range(1, Number + 1):
    value = int(input("Please enter the Value of %d Element : " %i))
    NumList.append(value)

while(j < Number):
    if(NumList[j] % 2 == 0):
        Even_Sum = Even_Sum + NumList[j]
    else:
        Odd_Sum = Odd_Sum + NumList[j]
    j = j+ 1

print("\nThe Sum of Even Numbers in this List =  ", Even_Sum)
print("The Sum of Odd Numbers in this List =  ", Odd_Sum)

OUTPUT

Python Program to find Sum of Even and Odd Numbers in a List 2

Python Program to Calculate Sum of Even and Odd Numbers in a List using Functions

This program is same as first example. However, we separated the logic using Functions

# Python Program to find Sum of Even and Odd Numbers in a List

def even_sum(NumList):
    Even_Sum = 0
    for j in range(Number):
        if(NumList[j] % 2 == 0):
            Even_Sum = Even_Sum + NumList[j]
    return Even_Sum

def odd_sum(NumList):
    Odd_Sum = 0
    for j in range(Number):
        if(NumList[j] % 2 != 0):
            Odd_Sum = Odd_Sum + NumList[j]
    return Odd_Sum

NumList = []
Number = int(input("Please enter the Total Number of List Elements: "))
for i in range(1, Number + 1):
    value = int(input("Please enter the Value of %d Element : " %i))
    NumList.append(value)

Even_Sum = even_sum(NumList)
Odd_Sum = odd_sum(NumList)
print("\nThe Sum of Even Numbers in this List =  ", Even_Sum)
print("The Sum of Odd Numbers in this List =  ", Odd_Sum)

OUTPUT

Python Program to find Sum of Even and Odd Numbers in a List 3