HackerRank Collections.namedtuple() solution in python | python question solution

collections.namedtuple()

Basically, namedtuples are easy to create, lightweight object types.
They turn tuples into convenient containers for simple tasks.
With namedtuples, you don’t have to use integer indices for accessing members of a tuple.

Example

Code 01

>>> from collections import namedtuple
>>> Point = namedtuple('Point','x,y')
>>> pt1 = Point(1,2)
>>> pt2 = Point(3,4)
>>> dot_product = ( pt1.x * pt2.x ) +( pt1.y * pt2.y )
>>> print dot_product
11

Code 02

>>> from collections import namedtuple
>>> Car = namedtuple('Car','Price Mileage Colour Class')
>>> xyz = Car(Price = 100000, Mileage = 30, Colour = 'Cyan', Class = 'Y')
>>> print xyz
Car(Price=100000, Mileage=30, Colour='Cyan', Class='Y')
>>> print xyz.Class
Y

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Task

Dr. John Wesley has a spreadsheet containing a list of student’s , ,  and .

Your task is to help Dr. Wesley calculate the average marks of the students.

Note:
1. Columns can be in any order. IDs, marks, class and name can be written in any order in the spreadsheet.
2. Column names are ID, MARKS, CLASS and NAME. (The spelling and case type of these names won’t change.)

The first line contains an integer , the total number of students.
The second line contains the names of the columns in any order.
The next  lines contains the , ,  and , under their respective column names.

Constraints

Print the average marks of the list corrected to 2 decimal places.

TESTCASE 01

5
ID         MARKS      NAME       CLASS     
1          97         Raymond    7         
2          50         Steven     4         
3          91         Adrian     9         
4          72         Stewart    5         
5          80         Peter      6   

TESTCASE 02

5
MARKS      CLASS      NAME       ID        
92         2          Calum      1         
82         5          Scott      2         
94         2          Jason      3         
55         8          Glenn      4         
82         2          Fergus     5

TESTCASE 01

78.00

TESTCASE 02

81.00

TESTCASE 01

Average = 

Can you solve this challenge in 4 lines of code or less?
NOTE: There is no penalty for solutions that are correct but have more than 4 lines.

Problem solution in Python 2 programming.

# Enter your code here. Read input from STDIN. Print output to STDOUT
from collections import namedtuple
N = int(raw_input())
headers = raw_input()
student = namedtuple('Student',headers)
students = []
for i in range(N):
    students.append(student(*raw_input().split()))
print sum(list(map(lambda x: float(x.MARKS),students)))/len(students)

Problem solution in Python 3 programming.

N, headers, total = int(input()), list(input().split()), 0
for _ in range(N):
    total += int(list(input().split())[headers.index('MARKS')])
print(total/N)

Problem solution in pypy programming.

# Enter your code here. Read input from STDIN. Print output to STDOUT
from collections import namedtuple
n, Student = input(), namedtuple('Student', raw_input())
print "%.2f" %( sum([float(stud.MARKS) for stud in [Student(*raw_input().split()) for _ in xrange(n)]]) / n )

Problem solution in pypy3 programming.

num_students = int(input())
relevant_pos = None
total = 0
for num in range(num_students + 1):
    if num == 0:
        titles = list(filter(lambda el: el != '', input().split(' ')))
        relevant_pos = titles.index('MARKS')
        continue
    total += int(list(filter(lambda el: el != '', input().split(' ')))[relevant_pos])

print(round(float(total) / num_students, 2))