Python bisect module and pythonbisect Module

Python bisect module and pythonbisect Module

The bisect module of Python is a built-in module. The bisect module implements an algorithm used to insert elements to an ordered list.

In some cases, this is more efficient than repeatedly sorting a list or constructing a large list and then sorting. Bisect is the meaning of the binary method, where binary sorting is used to insert the elements to be inserted to a proper position.

 

The bisect module provides the following functions:

(Lo and hi in the following function are used to specify the range of the list. The default value is the entire list)

Bisect. bisect_left (a, x, lo = 0, hi = len (a) returns the position where x is inserted into the index in list a. If x already exists, the position of the first x is returned.

Bisect. bisect_right (a, x, lo = 0, hi = len (a) returns x inserted to the index position in list a. If x already exists, returns the next position of the last x position.

Bisect. bisect (a, x, lo = 0, hi = len (a) is the same as bisect_right.

 

Bisect. insort_left (a, x, lo = 0, hi = len (a) insert x to list a. If there is already x, insert it to the leftmost of all x

Bisect. insort_right (a, x, lo = 0, hi = len (a) insert x to list a. If there is already x, insert it to the rightmost of all x

Bisect. insort (a, x, lo = 0, hi = len (a) is the same as insort_right

 

The following is an example:

>>> import bisect>>> import random>>> mylist = list()>>> for i in range(10):num = random.randint(1,100)index = bisect.bisect_left(mylist, num)bisect.insort_left(mylist, num)print('num  ', str(num), '\tindex  ', str(index), '\tlist ', mylist)num   37 index   0 list  [37]num   31 index   0 list  [31, 37]num   82 index   2 list  [31, 37, 82]num   27 index   0 list  [27, 31, 37, 82]num   62 index   3 list  [27, 31, 37, 62, 82]num   83 index   5 list  [27, 31, 37, 62, 82, 83]num   83 index   5 list  [27, 31, 37, 62, 82, 83, 83]num   87 index   7 list  [27, 31, 37, 62, 82, 83, 83, 87]num   98 index   8 list  [27, 31, 37, 62, 82, 83, 83, 87, 98]num   99 index   9 list  [27, 31, 37, 62, 82, 83, 83, 87, 98, 99]>>> mylist = list()>>> for i in range(10):num = random.randint(1,100)index = bisect.bisect_right(mylist, num)bisect.insort_right(mylist, num)print('num  ', str(num), '\tindex  ', str(index), '\tlist ', mylist)num   85 index   0 list  [85]num   73 index   0 list  [73, 85]num   82 index   1 list  [73, 82, 85]num   36 index   0 list  [36, 73, 82, 85]num   80 index   2 list  [36, 73, 80, 82, 85]num   4 index   0 list  [4, 36, 73, 80, 82, 85]num   79 index   3 list  [4, 36, 73, 79, 80, 82, 85]num   6 index   1 list  [4, 6, 36, 73, 79, 80, 82, 85]num   64 index   3 list  [4, 6, 36, 64, 73, 79, 80, 82, 85]num   25 index   2 list  [4, 6, 25, 36, 64, 73, 79, 80, 82, 85]>>> mylist = list()>>> for i in range(10):num = random.randint(1,100)index = bisect.bisect(mylist, num)bisect.insort(mylist, num)print('num  ', str(num), '\tindex  ', str(index), '\tlist ', mylist)num   25 index   0 list  [25]num   28 index   1 list  [25, 28]num   81 index   2 list  [25, 28, 81]num   9 index   0 list  [9, 25, 28, 81]num   29 index   3 list  [9, 25, 28, 29, 81]num   66 index   4 list  [9, 25, 28, 29, 66, 81]num   34 index   4 list  [9, 25, 28, 29, 34, 66, 81]num   60 index   5 list  [9, 25, 28, 29, 34, 60, 66, 81]num   61 index   6 list  [9, 25, 28, 29, 34, 60, 61, 66, 81]num   3 index   0 list  [3, 9, 25, 28, 29, 34, 60, 61, 66, 81]