my home work | Python Fiddle

def pair(x, y):
    """Return a function that represents a pair."""
    def get(index):
        if index == 0:
            return x
        elif index == 1:
            return y
        return get

def make_mutable_pair(key, value):
    """Return a functional implementation of a mutable pair."""
    records = []
    
    def get_item(key):
        for k, v in records:
            if k == key:
                return v
            
            def set_item(key, value):
                for item in records:
                    if item[0] == key:
                        item[1] = value
                        return                    
                    records.append([key, value])
                    
                    def dispatch(message, key=None, value=None):
                        if message == "get_item":
                        	return get_item(key)
                        elif message == "set_item":
                            set_item(key, value)
                        return dispatch
                    
p = make_mutable_pair(1,2)
p(‘get_item’, 0)

Browser Version Not Supported

Due to Python Fiddle's reliance on advanced JavaScript techniques, older browsers might have problems running it correctly. Please download the latest version of your favourite browser.
Chrome 10+ Firefox 4+ Safari 5+
IE 10+

Let me try anyway!

Python Fiddle

Python Cloud IDE