Python Loop Problems Archives - Page 8 Of 9

Find the first and last digits of a number.

In this program, we will find the first and last digits of a number.

Steps to solve the program

Take a number as input and convert it into a string using str().
Use for loop to iterate over indexes of the number.
Using logic print the first and last digits of a number.

				
					num = 2665
str1 = str(num)

for i in range(len(str1)):
    if i == 0:
        print("First number in the gievn number : ",str1[i])
    elif i == len(str1)-1:
        print("Last number in the gievn number : ",str1[i])

Output :

				
					First number in the gievn number :  2
Last number in the gievn number :  5

count the number of digits in a number

find the sum of the first and last digits of a number

Count the number of digits in a number

In this program, we will count the number of digits in a number.

Steps to solve the program

Take a number in string format as input.
Create a variable and assign its value equal to 0.
Use for loop to iterate over each digit of the number and during iteration add 1 to the created variable.
Print the final output.

				
					num = '12345'
count = 0

for ele in num:
    count += 1
    
print(f"Total digits in {num}: ",count)

Output :

				
					Total digits in 12345:  5

find the sum of all odd numbers between 1 to n

find the first and last digits of a number

Find the sum of odd numbers between 1 to n

In this program, we will find the sum of odd numbers between 1 to n.

Steps to solve the program

Use for loop with range function to iterate over numbers between 1-n.
Create a variable total and assign its value equal to 0.
During the iteration check, if the number is odd and add only those numbers to the total variable.
Print the output.

				
					n= int(input("Enter the last number: "))
total = 0

for i in range(1,n+1):
    if i%2 != 0:
        total += i
    
print(total)

Output :

find the sum of all even numbers between 1 to n

count the number of digits in a number

Find the sum of even numbers between 1 to n

In this program, we will find the sum of even numbers between 1 to n.

Steps to solve the program

Use for loop with range function to iterate over numbers between 1-n.
Create a variable total and assign its value equal to 0.
During the iteration check, if the number is even and add only those numbers to the total variable.
Print the output.

				
					n= int(input("Enter the last number: "))
total = 0

for i in range(1,n+1):
    if i%2 == 0:
        total += i
    
print(total)

Output :

find the sum of all natural numbers between 1 to n

find the sum of all odd numbers between 1 to n

Find the sum of natural numbers between 1-n

In this program, we will find the sum of natural numbers between 1 to n.

Steps to solve the program

Take n as the last natural number as input through the user.
Create a variable named total and assign its value equal to 0.
Use for loop with range function to iterate over 1-n natural numbers.
During each iteration add that number to the total.
Print the output.

				
					n= int(input("Enter the last number: "))
total = 0

for i in range(1,n+1):
    total += i
    
print(total)

Output :

print all odd numbers between 1 to 100

find the sum of all even numbers between 1 to n

Print all odd numbers between 1 to 100

In this program, we will print all odd numbers between 1 to 100.

Steps to solve the program

Use for loop with range function to iterate over each number from 1 to 100.
If a number is not divisible by 2 then only print the number.

				
					
for i in range(1,101):
    if i%2 != 0:
        print(i,end=" ")

Output :

				
					1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 
49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91
93 95 97 99

print all even numbers between 1 to 100

find the sum of all natural numbers between 1 to n

Print all even numbers between 1 to 100.

In this program, we will print all even numbers between 1 to 100.

Steps to solve the program

Use for loop with range function to iterate over each number from 1 to 100.
If a number is divisible by 2 then only print the number.

				
					
for i in range(1,101):
    if i%2 == 0:
        print(i,end=" ")

Output :

				
					2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 
44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 
84 86 88 90 92 94 96 98 100

program to print all alphabets from a to z

print all odd numbers between 1 to 100

Print all alphabets from a-z and A-Z

In this program, we will print all alphabets from a-z using a for loop.

Steps to solve the program

Import string.
Using for loop print all lowercase alphabets from a-z using string.ascii_lowercase.
Using for loop print all uppercase alphabets from a-z using string.ascii_uppercase.

Solution 1:

				
					import string

print("Alphabet from a-z:")
for letter in string.ascii_lowercase:
    print(letter, end =" ")

print("\nAlphabet from A-Z:")
for letter in string.ascii_uppercase:
    print(letter, end =" ")

Output :

				
					Alphabet from a-z:
a b c d e f g h i j k l m n o p q r s t u v w x y z 

Alphabet from A-Z:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Solution 2:

				
					# small letter ascii range from 97-122
print("Alphabet from a-z")
for i in range(26):
    # increase small letter ascii value by 1
    # and print character with ascii value
    print(chr(97 + i), end=' ')

# capital letter ascii range from 65-90
print("\nAlphabet from A-Z")
for i in range(26):
    # increase capital letter ascii value by 1
    # and print character with ascii value
    print(chr(65 + i), end=' ')

Output :

				
					Alphabet from a-z:
a b c d e f g h i j k l m n o p q r s t u v w x y z 

Alphabet from A-Z:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

print all natural numbers in reverse

print all even numbers between 1 to 100

Print all natural numbers in reverse (n to 1)

In this program, we will print all natural numbers in reverse (from n to 1) using a while loop

Steps to solve the program

Take the last number from which you want to print the natural numbers as input through the user.
Create a variable count and assign its value equal to the input number.
Use a while loop to print the numbers in reverse order.
While the count variable is not equal to 0 print count and subtracts 1 from it each time.
Print the output.

				
					n = int(input("Enter the last number: "))
count = n

while count != 0:
    print(count,end=" ")
    count -= 1

Output :

				
					Enter the last number: 10
10 9 8 7 6 5 4 3 2 1

print all natural numbers from 1 to n

program to print all alphabets from a to z

Print all natural numbers from 1 to n

In this program, we will print all natural numbers from 1 to n using a while loop.

Steps to solve the program

Take the number up to which you want to print natural numbers from the user.
Create a variable count and assign its value equal to 1.
Use a while loop to print the natural numbers up to the input number.
While the value of the count variable is less than the input number print count and add 1 to the count variable.
Print the output.

				
					n = int(input("Enter the last number: "))
count = 1

while count <= n:
    print(count,end=" ")
    count += 1

Output :

				
					Enter the last number: 10
1 2 3 4 5 6 7 8 9 10

print the alphabet pattern ‘O’

print all natural numbers in reverse