f | |
| :mod:`bisect` --- Array bisection algorithm |
| =========================================== |
| |
| .. module:: bisect |
| :synopsis: Array bisection algorithms for binary searching. |
| .. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org> |
n | |
| |
| .. % LaTeX produced by Fred L. Drake, Jr. <fdrake@acm.org>, with an |
| .. % example based on the PyModules FAQ entry by Aaron Watters |
| .. example based on the PyModules FAQ entry by Aaron Watters <arw@pythonpros.com> |
| .. % <arw@pythonpros.com>. |
| |
| This module provides support for maintaining a list in sorted order without |
| having to sort the list after each insertion. For long lists of items with |
| expensive comparison operations, this can be an improvement over the more common |
| approach. The module is called :mod:`bisect` because it uses a basic bisection |
| algorithm to do its work. The source code may be most useful as a working |
| example of the algorithm (the boundary conditions are already right!). |
| |
| Examples |
| -------- |
| |
| .. _bisect-example: |
| |
| The :func:`bisect` function is generally useful for categorizing numeric data. |
| This example uses :func:`bisect` to look up a letter grade for an exam total |
| (say) based on a set of ordered numeric breakpoints: 85 and up is an 'A', 75..84 |
t | is a 'B', etc. :: |
t | is a 'B', etc. |
| |
| >>> grades = "FEDCBA" |
| >>> breakpoints = [30, 44, 66, 75, 85] |
| >>> from bisect import bisect |
| >>> def grade(total): |
| ... return grades[bisect(breakpoints, total)] |
| ... |
| >>> grade(66) |