txt1 = "{0} lucky number is {1}".format("John Doe", 45)
txt2 = "{} lucky number is {}".format("John Doe", 45)
txt3 = "{name} lucky number is {num}".format(name = "John Doe", num = 45)
print(txt1)
print(txt2)
print(txt3)
OUTPUT
John Doe lucky number is 45
John Doe lucky number is 45
John Doe lucky number is 45