Python Cookbook 2Nd Edition Jun 1002005 [Electronic resources]

Recipe 1.4. Aligning Strings

Credit: Luther Blissett

Problem

You want to align strings: left, right, or center.

Solution

That's what the ljust, rjust, and center methods of string objects are for. Each takes a single argument, the width of the string you want as a result, and returns a copy of the starting string with spaces added on either or both sides:

>>> print '|', 'hej'.ljust(20), '|',
 'hej'.rjust(20), '|', 'hej'.center(20), '|'
| hej             |             hej |       hej       |

Discussion

Centering, left-justifying, or right-justifying text comes up surprisingly oftenfor example, when you want to print a simple report with centered page numbers in a monospaced font. Because of this, Python string objects supply this functionality through three of their many methods. In Python 2.3, the padding character is always a space. In Python 2.4, however, while space-padding is still the default, you may optionally call any of these methods with a second argument, a single character to be used for the padding:

>>> print 'hej'.center(20, '+')
++++++++hej+++++++++

See Also

The Library Reference section on string methods; Java Cookbook recipe 3.5.