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Python Program to Print Negative Numbers in a List

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Write a Python Program to Print Negative 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 Print Negative Numbers in a List using For Loop

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

# Python Program to 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 = '   ')

OUTPUT

Python Program to Print Negative Numbers in a List 1

ANALYSIS
User entered List elements = [2, -12, 0, -17]

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] < 0) => if(2 < 0) – Condition is False
This Number is 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 is printed.

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

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

Fifth Iteration: for 4 in range(0, 4) – Condition is False
So compiler will exit from For Loop

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

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

# Python Program to Print Negative Numbers in a List

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

OUTPUT

Python Program to Print Negative Numbers in a List 2

Python Program to find Negative Numbers in a List using Functions

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

# Python Program to Print Negative Numbers in a List

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)

OUTPUT

Python Program to Print Negative Numbers in a List 3