Question

For example:

print('items %05d'%12)

would print 00012.

Can the amount of padding be specified by a variable instead of a literal? I believe python 2.6+ has the .format function but what are the options with python 2.5?

Answer 1

You can replace the width number with a * and the Python % substitution will expect an integer value, and use that for the width. Since you will now have at least two values for the % operator (one width and one actual value) you will need to make a tuple to pass them together.

print "items %0*d" % (5, 12)

If you leave out the 0 before the * you will get padding with spaces rather than 0.

Documented here:

http://docs.python.org/release/2.5.2/lib/typesseq-strings.html

Section 3.6.2, rule 4.