basic operations on Jupyter notebook python data science

basic operations on Jupyter notebook:

value = 50
print (value)
PI = 3.1416 #PI number

radio = input("Please, enter the radius of the circumference: ") #ask the user to enter some value
longitud = 2 * PI * float(radio) #calculation
print("The length of the circumference is: ", round(longitud,2))