Write a Python program to find a missing number from a list

Title : Write a Python program to find a missing number from a list

Description : 

Write a Python program to find a missing number from a list

Source Code:

def missing_number(num_list):

    return sum(range(num_list[0],num_list[-1]+1)) - sum(num_list)

print(missing_number([1,2,3,4,6,7,8]))

print(missing_number([10,11,12,14,15,16,17]))

Sample Output:

5                                                                                                             
13