Using the bisect module

This module provides functions to insert items in sorted sequences.

insort(sequence, item) inserts item into the sequence, keeping it sorted. The sequence can be any mutable sequence object that implements __getitem__ andinsert.

Example: Using the bisect module to insert items in an ordered list

# File: bisect-example-1.py

import bisect

list = [10, 20, 30]

bisect.insort(list, 25)
bisect.insort(list, 15)

print list

$ python bisect-example-1.py
[10, 15, 20, 25, 30]

bisect(sequence, item) ⇒ index returns the index where the item should be inserted. The sequence is not modified.

Example: Using the bisect module to find insertion points

# File: bisect-example-2.py

import bisect

list = [10, 20, 30]

print list
print bisect.bisect(list, 25)
print bisect.bisect(list, 15)

$ python bisect-example-2.py
[10, 20, 30]
2
1

衍伸閱讀
generating ASCII art from photographs in Python
http://stevendkay.wordpress.com/2009/09/08/generating-ascii-art-from-photographs-in-python/