human
I am working on the file "Python/Chapter-07/ListMap.ipynb".
The first task is:
A MapIterator is an iterator that iterates over the elements of a linked list.  It maintains a pointer mPtr that points to the next element.
It is implemented via the function __next__.  This function either returns the next key-vale pair or, if there are no more key-value pairs left, then it raises a
StopIteration exception.
If the __iter__ method of a class $C$ returns an iterator, then we can use a 
for-loop to iterate over the elements contained in class $C$.
Can you write Python program for it?
assistant
#Here is the Python program you requested.

class MapIterator:
    def __init__(self, ptr):
        self.mPtr = ptr
    
    def __next__(self):
        if self.mPtr == None:
            raise StopIteration
        key   = self.mPtr.mKey
        value = self.mPtr.mValue
        self.mPtr = self.mPtr.mNextPtr
        return key, value

def main(n = 100):
    S = ListMap()
    for i in range(2, n + 1):
        S.insert(i, True)
    for i in range(2, n // 2 + 1):
        for j in range(i, n // i + 1):
            S.delete(i * j)
    print([p for p, _ in S]) # iterates over ListMap
    print(S.find(83))
    print(S.find(99))

main()