Lecture 8 Import file 

x=1
def a():
    print("Hello a")
a()
# case 1 import module as label
import dio as d
d.a()
print (x,d.x,d._x)
# case 2 from module import *

from dio import *
a()
print (x, x_y)

from tria import *
a()
print (x)

# case from module import selected items
from tria import a, _x
a()
print (_x)
from math import pi,sqrt
print(pi,sqrt(9089809))