String formatting: % vs. .format

Question

In Python 2.6, the str.format() has been introduced and has a slightly different syntax than existing % operator. When should I use which one and who's better? I tried this and used each method and the outcome I received is same, then what's the difference between two of them? #!/usr/bin/python sub1 = "an Amimal!" sub2 = "horn" q = "It's me %s" % sub1 w = "It's me {0}".format(sub1) e = "with big %(kwarg)s!" % {'kwarg':sub2} r = "with big {kwarg}!".format(kwarg=sub2) print q # "It's me an animal!" print w # "It's me an animal!" print e # "with big horn!" print r # "with big horn!" I am also confused when string formatting occurs in Python? Is this happen when my logging level is set to High will I still have a problem while performing the following % operation? And if this is true than how can I avoid this? log.debug("some debug info: %s" % some_info) Select the correct answer from above options

Answer 1

% either takes a variable or a tuple whereas .format don't have these issues, for instance check this: "hi there %s" % name for your second doubt, I assume you're using logging module , then try this: log.debug("some debug info: %s", some_info) This will avoid all formatting unless your logger logs something.