Python uses C-style string formatting to create new, formatted strings. The "%" operator is used to format a set of variables enclosed in a "tuple" (a fixed size list), together with a format string, which contains normal text together with "argument specifiers", special symbols like "%s" and "%d".
Let's say you have a variable called "name" with your user name in it, and you would then like to print out a greeting to that user.
# This prints out "Hello, John!" name = "John" print "Hello, %s!" % name
To use two or more argument specifiers, use a tuple (parentheses):
# This prints out "John is 23 years old." name = "John" age = 23 print "%s is %d years old." % (name, age)
Any object which is not a string can be formatted using the %s operator as well. The string which returns from the "repr" method of that object is formatted as the string. For example:
# This prints out: A list: [1, 2, 3] mylist = [1,2,3] print "A list: %s" % mylist
Here are some basic argument specifiers you should know:
%s - String (or any object with a string representation, like numbers) %d - Integers %f - Floating point numbers %.<number of digits>f - Floating point numbers with a fixed amount of digits to the right of the dot. %x/%X - Integers in hex representation (lowercase/uppercase)
You will need to write a format string which prints out the data using the following syntax: Hello John Doe. Your current balance is 53.44$.
data = ("John", "Doe", 53.44) format_string = "Hello" print format_string % data
Hello John Doe. Your current balance is 53.44$.