old_contents: # Exercise_01
  # Write a Python program which accepts the radius of a circle from the user and compute the area
   
  from math import pi
  
  print('Exercise_01')
  
  radius = float(input ('Input the radius of the circle: '))
  area = (pi * radius**2)
  print('The area of the circle with radius ' + str(radius) + ' is ' + str(area))
  
  
new_contents: # -------------------------------------------------------------------------------------------------
  # Exercise_01
  # Write a Python program which accepts the radius of a circle from the user and compute the area
   # -------------------------------------------------------------------------------------------------
  
  from math import pi
  
  print('Exercise_01')
  
  radius = float(input ('Input the radius of the circle: '))
  area = (pi * radius**2)
  print('The area of the circle with radius ' + str(radius) + ' is ' + str(area) + '\n\n')
  
  # -------------------------------------------------------------------------------------------------
  # Exercise_02
  # Write a Python program to calculate number of days between two dates
  # -------------------------------------------------------------------------------------------------
  
  from datetime import date
  
  print('Exercise_02')
  
  yy = int(input('Input the start date year: '))
  mm = int(input('Input the start date month: '))
  dd = int(input('Input the start date day: '))
  start_date = date(yy,mm,dd)
  
  yy = int(input('Input the finish date year: '))
  mm = int(input('Input the finish date month: '))
  dd = int(input('Input the finish date day: '))
  finish_date = date(yy,mm,dd)
  
  diff = (finish_date - start_date)
  
  print('Number of days between ' + str(start_date) + ' and ' + str(finish_date) + ' is ' + str(diff))
  
  # -------------------------------------------------------------------------------------------------
  # -------------------------------------------------------------------------------------------------
subject: Add new exercise to Math.py