binary search algorithm in python code example

Example 1: iterative binary search python

def binary_search(a, key):
	low = 0
	high = len(a) - 1
	while low < high:
		mid = (low + high) // 2
		if key == a[mid]:
			return True
		elif key < mid:
			high = mid - 1
		else:
			low = mid + 1

	return False

Example 2: binary search in python

def binary_search(item_list,item):
	first = 0
	last = len(item_list)-1
	found = False
	while( first<=last and not found):
		mid = (first + last)//2
		if item_list[mid] == item :
			found = True
		else:
			if item < item_list[mid]:
				last = mid - 1
			else:
				first = mid + 1	
	return found

Example 3: binary search in python

def binary_search(group, suspect):
  group.sort()
  midpoint = len(group)//2
  while(True):
    if(group[midpoint] == suspect):
      return midpoint
    if(suspect > group[midpoint]):
            group = group[midpoint]
    if(suspect < group[midpoint]):
      group = group[0: midpoint]
    midpoint = (len(group)//2)

Example 4: code of binary search in python

def binary_search(mylist,low,k,key):
    high = k - 1
    mid = (low + high)//2
    
    if mylist[mid]==key:
        return mid
    elif key > mylist[mid]:
        return binary_search(mylist,mid + 1,k ,key)
    else:
        return binary_search(mylist,0,mid, key)
low = 0
k = int(input("Enter total amount of elements in k : "))
mylist = [int(input()) for x in range(k)]
key = int(input("Which element do  we have to find: "))
print(binary_search(mylist,low,k,key))