Nested Dictionary

Lab Python Intermediate 20 points

Read n lines student subject mark. Store marks in a nested dict {student: {subject: mark}}. Then print each student (sorted) with their average mark to 1 decimal place.

Input

Line 1: n. Then n lines.

Output

student average per line.

Example

Input

4
ann math 90
ann art 71
bob math 60
bob art 66

Output

ann 80.5
bob 63.0

Sample input available Sample output available

Editor

Python

Hints

marks.setdefault(student, {}) creates the inner dict on first use.

values() gives just the marks.

Solution explanation

Nested dicts model structured data, like JSON.

Show solution

n = int(input())
marks = {}
for _ in range(n):
    student, subject, mark = input().split()
    marks.setdefault(student, {})[subject] = int(mark)
for student in sorted(marks):
    subjects = marks[student]
    print(f"{student} {sum(subjects.values()) / len(subjects):.1f}")

Output

Answer