Question

In Python there seem to be two different ways of generating formatted output:

user = "Alex"
number = 38746
print("%s asked %d questions on stackoverflow.com" % (user, number))
print("{0} asked {1} questions on stackoverflow.com".format(user, number))

Is there one way to be preferred over the other? Are they equivalent, what is the difference? What form should be used, especially for Python3?

Answer 1

Use the format method, especially if you’re concerned about Python 3 and the future. From the documentation:

The formatting operations described here are modelled on C’s printf()
syntax. They only support formatting of certain builtin types. The
use of a binary operator means that care may be needed in order to
format tuples and dictionaries correctly. As the new
:ref:string-formatting syntax is more flexible and handles tuples and
dictionaries naturally, it is recommended for new code. However, there
are no current plans to deprecate printf-style formatting.