Need some help with Python problem, fix bugs(in picture 2, the function countinuequeue_ier):

class CountingQueue(object): def __init__(self): self.queue = [] def __repr__(self): return repr(self.queue) def add(self, x, count=1): # If the element is the same as the last element, we simply # increment the count. This assumes we can test equality of # elements. if len(self.queue) > 0: xx, cc = self.queue[-1] if xx == x: self.queue[-1] = (xx, cc + count) else: self.queue.append((x, count)) else: self.queue = [(x, count)] def get(self): if len(self.queue) == 0: return None x, c = self.queue[0] if c == 1: self.queue.pop(0) return x else: self.queue[0] = (x, c - 1) return x def isempty(self): # Since the count of an element is never 0, we can just check # whether the queue is empty. return len(self.queue) == 0

def countingqueue_iter(self):

"""Iterates through all the elements of the queue,

without removing them."""

for i in range(len(self.queue)):

yield self.queue[i]

# This is a way to add a method to a class once the class

# has already been defined.

CountingQueue.__iter__ = countingqueue_iter

CountingQueue.__len__=countingqueue_len

Testing:

try: from nose.tools import assert_equal, assert_almost_equal from nose.tools import assert_true, assert_false from nose.tools import assert_not_equal, assert_greater_equal except: !pip install nose from nose.tools import assert_equal, assert_almost_equal from nose.tools import assert_true, assert_false from nose.tools import assert_not_equal, assert_greater_equal

q = CountingQueue() for i in range(10): q.add('a') q.add('b') for i in range(3): q.add('c', count=2) l1 = [x for x in q] l2 = [] while not q.isempty(): l2.append(q.get()) assert_equal(l1, l2)

During lecture, we implemented an iterator for the Queue class using the generator technique. For this exercise, you will use that same technique to implement an iterator for CountingQueue. Note: this can be done elegantly in 3 lines of code. I def countingqueue_iter(self): *"Iterates through all the elements of the queue, without removing them. *** for i in range(len(self.queue)): yield self.queue[i] # This is a way to add a method to a class once the class # has already been defined. CountingQueue. _iter__ = countingqueue_iter CountingQueue. _len_=countingqueue_len All Tests for 'CountingQueue. _iter_ 9 = CountingQueue () for i in range(10): 4.add('a') 9.add('') 4.add('c', count=2) 11 = (x for x in 4] 12 = [] while not q. isempty(): 12.append(9.get() assert_equal(11, 12) AssertionError Traceback (most recent call last) in () 10 while not q. isempty(): 11 12.append(9.get() ---> 12 assert_equal(11, 12) - 3 frames - /usr/lib/python3.6/unittest/case.py in fail(self, mg) 668 def fail(self, msg=None): ****"Fail immediately, with the given message." raise self. failureException(msg) 671 672 def assertFalse(self, expr, asg-None): AssertionError: Lists differ: [('a', 10), ('b', 1), ('c', 6)] != ['a', 'a', 'a', 'a', 'a', 'a', 'a', 'a', '(38 chars] 'c'] First differing elemente: ('a', 1e) Second list contains 14 additional elements. First extra element 3: - [('a', 18), ('b', 1), ('C', 6)] + 'a