Python Program to Count Positive and Negative Numbers in a List

Write a Python Program to Count Positive and Negative Numbers in a List using For Loop, While Loop, and Functions with a practical example.

Python Program to Count Positive and Negative Numbers in a List using For Loop

In this python program, we are using For Loop to iterate every element in a given List. Inside the Python for loop, we are using the If statement to check and count Positive and Negative numbers.

# Python Program to Count Positive and Negative Numbers in a List

NumList = []
Positive_count = 0
Negative_count = 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] >= 0):
        Positive_count = Positive_count + 1
    else:
        Negative_count = Negative_count + 1

print("\nTotal Number of Positive Numbers in this List =  ", Positive_count)
print("Total Number of Negative Numbers in this List = ", Negative_count)

OUTPUT

ANALYSIS

In this python program, the User entered List elements = [12, -22, 3, 5], Positive_count = 0, Negative_count = 0

For Loop – First Iteration: for 0 in range(0, 4)
The condition is True. So, it enters into the If Statement
if(NumList[0] >= 0) => if(12 >= 0) – Condition is True
Positive_count = Positive_count + 1 => 0 + 1 = 1

Second Iteration: for 1 in range(0, 4) – Condition is True
if(NumList[1] >= 0) => if(-22 >= 0) – Condition is False, so it enters the Else block.
Negative_count = Negative_count + 1 => 0 + 1 = 1

Third Iteration: for 2 in range(0, 4) – Condition is True
if(NumList[2] >= 0) => if(3 >= 0) – Condition is True
Positive_count = 1 + 1 => 2

Fourth Iteration: for 3 in range(0, 4) – Condition is True
if(5 >= 0) – Condition is True. So, it enters into the Else block.
Positive_count = 2 + 1 => 3

Fifth Iteration: for 4 in range(4) – Condition is False. So, Python exits from For Loop

Python Program to Count Positive and Negative Numbers in a List using While loop

This Python program for counting positive and negative numbers is the same as the above. We just replaced the For Loop with While loop.

# Python Program to Count Positive and Negative Numbers in a List

NumList = []
Positive_count = 0
Negative_count = 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] >= 0):
        Positive_count = Positive_count + 1
    else:
        Negative_count = Negative_count + 1
    j = j + 1

print("\nTotal Number of Positive Numbers in this List =  ", Positive_count)
print("Total Number of Negative Numbers in this List = ", Negative_count)

OUTPUT

Python Program to Count Positive and Negative items in a List using Functions

This Python counting positive and negative list items program is the same as the first example. However, we separated the logic using Functions

# Python Program to Count Positive and Negative Numbers in a List

def count_Positive(NumList):
    Positive_count = 0
    for j in range(Number):
        if(NumList[j] >= 0):
            Positive_count = Positive_count + 1
    return Positive_count

def count_Negative(NumList):
    Negative_count = 0
    for j in range(Number):
        if(NumList[j] % 2 != 0):
            Negative_count = Negative_count + 1
    return Negative_count

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)

Positive_cnt = count_Positive(NumList)
Negative_cnt = count_Negative(NumList)
print("\nTotal Number of Positive Numbers in this List =  ", Positive_cnt)
print("Total Number of Negative Numbers in this List = ", Negative_cnt)

OUTPUT