Detect if a set of numbers is complete and consecutive

isComplete.py

#!/bin/env python
# coding: utf-8

items = [
            [1, 2, 3, 5, 6, 7, 7, 8, 9, 10,11,12],  # false
            [2, 3, 4, 5, 6, 7, 8, 9, 10,11,12],     # false
            [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],        # true
            [1, 2, 2, 4, 5, 6, 7] ,                 # false
            [1, 2, 3, 4, 5, 7] ,                    # false
            [3, 5, 1, 2, 4]                         # true
        ]

def isComplete(numberSet):
    numberSet.sort()
    length = len(numberSet)
    expected = range(1, numberSet[-1]+1)
    if(length != numberSet[-1]):
        return False

    return (expected == numberSet)


for nums in items:
    print(isComplete(nums))