python format specifier
# Python3 program to demonstarte
# the str.format() method
# using format option in a simple string
print ("{}, A computer science portal for geeks."
.format("GeeksforGeeks"))
# using format option for a
# value stored in a variable
str = "This article is written in {}"
print (str.format("Python"))
# formatting a string using a numeric constant
print ("Hello, I am {} years old !".format(18))