"""Python implementation of Binary Heap."""

class Binheap(object):

"""Python implementation of max binary heap.

supports the following method

push(): puts a new value into the heap, maintaining the heap property.

pop(): removes the top value in the heap, maintaining the heap property.

dislplay(): displays the heap as a string representation of a tree.

"""

def __init__(self, data=None):

"""Initialize bin heap."""

self.container = [None]

if data:

for val in data:

self.push(val)

def _balance(self):

"""Helper function to balance heap."""

size = len(self.container) - 1

while size // 2 > 0:

if self.container[size] > self.container[size // 2]:

tmp = self.container[size // 2]

self.container[size // 2] = self.container[size]

self.container[size] = tmp

size = size // 2

def push(self, val):

"""Put a new value into the heap."""

self.container.append(val)

self._balance()

def pop(self):

"""Remove the top value of the heap."""

if not self.container:

raise IndexError('Can\'t pop from and empty heap')

self.container.pop(1)

self._balance()

def display(self):

"""Display the heap as a tree."""

cols = []

col = 1

to_show = ''

l = self.container[1:]

while len(self.container) > col:

cols.append(col)

col *= 2

for i, v in enumerate(cols):

buff = cols[-1 - i] // 2

to_show += buff * ' '

for idx in range(v):

if l:

to_show += str(l.pop(0)) + ' '

to_show += '\n'

return to_show