Python heapq example : Different Scenarios with Implementation

Python heapq example makes easy to understand heap data structure in Python.Python heapq has three main function ( heapify(),heappop(),heappush() ).

Various python heapq examples –

Lets see some examples. It will easily make you understand the concepts of heap in python.

1. python heapq example (heapify()):

If we have any iterable object like list, tuple, We can convert it to heap.Using the above heapify function.Lets see an example for heap creation in python.

import heapq 
#any list, tuple or any tother iterable obj
iterable_obj = [15, 71, 9, 11, 13] 
# heap conversions
heapq.heapify(iterable_obj) 
print (iterable_obj)

Here we have used a list object as iterable. After applying heapify operation over this list the minimum value come at the top. In our example the min value was “9”. Hence it is coming at first indices in heap (min).

2. heappush() example:

When we need to insert a new element in already created heap object. We use this heappush() function heapq python module.Lets checkout and example.

If we create a new node or insert a new value in heap. It will reconstruct and whole heap object. Hence again the smallest element will be on the root place.

heapq.heappush(iterable_obj,2)

In the above example, We have inserted an new element “2” in the heap. It has reshuffle the position of reach element in the heap. But the smallest element is on the root.

3. heappop() example :

This function will always pop the smallest value from the heap.Lets apply the heappop() function in the heap which we have created in the above sections.

print("Heap before appling tge heappop()")
print(iterable_obj)
#appling heappop()
print(heapq.heappop(iterable_obj)) 
print("Heap after appling tge heappop()")
print(iterable_obj)

4. Others heapq functions:

4.1 heapreplace() :

It will fist heappop() the object. After this it will push the new element. Hence It is a chain of the heappop() and heappush() operation.

4.2 heappushpop():

This a little different then the above heapreplace() function. It will first push the element in the heap. Then it will heappop() the complete object.

Thanks

Data Science Learner Team