∑ Home ◇ Math ◇ Computing ◇ Arts ◇ Words ◇ Literature ◇ Music ◆

Perl ＆ Python: Formatting Strings

Xah Lee, 2005-01-20

Python

There are several ways to format output strings. repr() is for turning a data into a string form that can be read back into Python. str() is focused on human readable form.

# Python
s = 3.14159
print str(s)
print repr(s)

# the repr() function has some methods for formatting
for x in range(1,5):
     print repr(x).rjust(2), repr(x*x).rjust(3)

The “print” function itself supports string formatting in the style of C's printf.

#-*- coding: utf-8 -*-
# python

# the “print” support C's printf style of formatting
print '%2d %6d %2.4f %s' % (1234, 5678, 3.1415926, 'Oh, dear!')

To print without the automatic line ending, use sys.stdout.write. Example:

# python
import sys
sys.stdout.write("something in the water")
sys.stdout.write(" does not compute")

Perl

In perl, if you want to print arrays or hashes for later reading into perl program, you'll need to use Data::Dumper module.

For formatting strings, you can use “printf” and “sprintf”.