Python Program to Print Negative Numbers in a List

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

In this program, we are using For Loop to iterate each element in this List. Inside the for loop, we are using the If statement to check and print Negative numbers in a list.

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)

print("\nNegative Numbers in this List are : ")
for j in range(Number):
    if(NumList[j] < 0):
        print(NumList[j], end = '   ')

In this Python program, the User entered List elements = [2, -12, 0, -17]

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( 2 < 0 ) – Condition is False
This Number was skipped.

Second Iteration: for 1 in range(0, 4) – Condition is True
if(NumList[1] < 0) => if( -12 < 0 ) – Condition is True
This Negative Number will print.

Third Iteration: for 2 in range(0, 4) – Condition is True
if(NumList[2] < 0) => if( 0 < 0 ) – Condition is False
This Number was skipped.

Fourth Iteration: for 3 in range(0, 4) – Condition is True
if( -17 < 0 ) – Condition is True
This Negative Number will print.

Fifth Iteration: for 4 in range(0, 4) – Condition is False
So, it exits from Python For Loop

Python Program to Print Negative Numbers in a List using While loop

This program for Negative numbers in a list is the same as the above. We just replaced the For Loop with the While loop.

NumList = []
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)

print("\nNegative Numbers in this List are : ")
while(j < Number):
    if(NumList[j] < 0):
        print(NumList[j], end = '   ')
    j = j + 1

Print Negative numbers in a list using a while loop output

Please enter the Total Number of List Elements: 5
Please enter the Value of 1 Element : 12
Please enter the Value of 2 Element : -13
Please enter the Value of 3 Element : -15
Please enter the Value of 4 Element : 3
Please enter the Value of 5 Element : -22

Negative Numbers in this List are : 
-13 -15 -22

Python Program to print Negative Numbers in a List using Functions

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

def negative_number(NumList):
    for j in range(Number):
        if(NumList[j] < 0):
            print(NumList[j], end = '   ')


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)

print("\nNegative Numbers in this List are : ")
negative_number(NumList)

Print Negative list numbers using functions and for loop output.

Please enter the Total Number of List Elements: 6
Please enter the Value of 1 Element : -12
Please enter the Value of 2 Element : 5
Please enter the Value of 3 Element : -7
Please enter the Value of 4 Element : -8
Please enter the Value of 5 Element : 9
Please enter the Value of 6 Element : -10

Negative Numbers in this List are : 
-12 -7 -8 -10