Python built-in data structures

Key 1: Understanding Python's in-built data structure.

Before going in on how to use different data structures, we should take a look at the attributes of the object that are important for built-in data structures. For the default sorting to work, the object should have one of the __lt__, and __gt__ methods defined. Otherwise, we can pass a key function to the sorting method to use in getting the intermediate keys that are used to compare it, as shown in the following code:

def less_than(self, other):
    return self.data <= other.data


class MyDs(object):

    def __init__(self, data):
        self.data = data

    def __str__(self,):
        return str(self.data)
    __repr__ = __str__

if __name__ == '__main__':

    ml = [MyDs(i) for i in range(10, 1, -1)]
    try:
        ml.sort()
    except TypeError:
        print("unable to sort by default")

    for att in '__lt__', '__le__', '__gt__',...