def add(x,y):
   z=x+y
   print ("x={} y={} x+y={}".format(x,y,z))

a=10
b=20
add(a,b)

x=10 y=20 x+y=30

add(b)
TypeError: add() missing 1 required positional argument: 'y'

add(10, 20, 30)
TypeError: add() takes 2 positional arguments but 3 were given

a="Hello"
b=20
add(a,b)

z=x+y
     ~^~
TypeError: can only concatenate str (not "int") to str