# Syntax of using the flag variable to validate an input

flag = False
while not flag:
     if [put condition here]:
            flag = True
     else:
          print('Input is not Valid')

# Syntax of using the try-except code block to validate an input

# Starting a while loop to always run this code
while True:
        # Starting a try block
        try:
            [Here, put the code which may contain an error]
       except:

print('This error message will be displayed if the code will have any error')

print('If the code written in the try block of the code above runs successfully, execute the code further from this point.')

# Python program to show how to use the flag variable to check the data type of the input variable

# Declaring a variable valid, which will work as a flag variable and will set it to False
valid = False

# Giving the flag variable as the condition of the while loop
# If the condition is true, it will prompt us to enter the input
while not valid:
    #The user will be prompted to give the input
    number = input('Please type a number: ')
    # We will check the input given by the user to see if it is of int data type
    if number.isdigit():
        #The flag variable is set to true if the condition in this if statement is true
        valid = True
    else:
        print('The input given is not a valid integer')
        # This will print this output if the input given by the user is of integer data type
    print('The given input is an integer and that is: ' + str(number))

Please type a number: 8.8
The input given is not a valid integer
The given input is an integer and that is: 8.8

# Python program to show how to use the flag variable to check the range of the input variable lies in the specified range

# Declaring a variable valid, which will work as a flag variable and will set it to False
valid = False

# Giving the flag variable as the condition of the while loop
# If the condition is true, it will prompt us to enter the input
while not valid:
    # The user will be prompted to give the input
    number = int(input('Please type a number: '))
    # We will check the input given by the user to see if it lies in the specified range
    if number >= 13 and number <= 19:
        valid = True
    else:
      print('The number given by you does not lie between 13 and 19')
    # This output will be printed if the input given by the user lies between the specified range
    print('The number given by the user lies between 13 and 19 and the number given by you is: ' + str(number))

Please type a number: 7
The number given by you does not lie between 13 and 19
The number given by the user lies between 13 and 19 and the number given by you is: 7

# Python program to show how to use the flag variable to check the range of the input variable

# Declaring a variable valid, which will work as a flag variable and will set it to False
valid = False

# Giving the flag variable as the condition of the while loop
# If the condition is true, it will prompt us to enter the input
while not valid:
    #The user will be prompted to give the input
    string = input('Please give a string: ')
    # We will check the input given by the user to see if it has a length greater than or equal to 5
    if len(string) >= 5:
        #The flag variable is set to true if the condition in this if statement is true
        valid = True
    else:
        print('The input string given has length less than 5')
        #This output will be printed if the input string given by the user has a specified length
    print('The given input string has a length greater than or equal to 5, and the string is: ' + string)

Please give a string: Python
The given input string has a length greater than or equal to 5, and the string is: Python