Nested list with python basic

Question

Given the names and grades for each student in a class of N students, store them in a nested list and print the name(s) of any student(s) having the second lowest grade.

Note: If there are multiple students with the second lowest grade, order their names alphabetically and print each name on a new line.

Example

 reords = [['chi', 20.0], ['bela', 50.0], ['alpha', 50.0]]

The ordered list of scores is [20.0, 50.0], so the second lowest score is 50.0 There are two students with that score:['beta', 'alpha'] . Ordered alphabetically, the names are printed as:

Input format:

The first line contains an integer, N, the number of students. The 2N subsequent lines describe each student over 2 lines.

The first line contains a student's name.
The second line contains their grade.

Output Format

Print the name(s) of any student(s) having the second lowest grade in. If there are multiple students, order their names alphabetically and print each one on a new line.

Example of input: Sample Input 0

 5
 Harry
 37.21
 Berry
 37.21
 Tina
 37.2
 Akriti
 41
 Harsh
 39

Sample Output 0

 Berry
 Harry

This my proposition code:

if __name__ == '__main__':
    student = []
    values = []
    names =[]
    for _ in range(int(input())):
        name = input()
        score = float(input())
        student.append([name, score])

    for item in student:
        values.append(item[1])
    values=list(set(values))
    values.sort()

    for item in student:
        if item[1] == values[1]:
            names.append(item[0])
    names.sort()

    for name in names:
        print(name)

when I run the code on jupiter Notebook I have the same resume. But when I run the same code in the éditor of the test I have an error. I don't understand enter image description here

I am pretty sure a verry similar quesiton was already asked here — Matiiss
– Matiiss, Commented Apr 19, 2021 at 12:41
The error is saying there are certain inputs that your code doesn't work with. Test it with the full input in your screenshot and see what happens. — Peter
– Peter, Commented Apr 19, 2021 at 12:42
I don't know, but I want to have more explanation to this problem. please look the image to see what I want to talk about — Amoungui Serge
– Amoungui Serge, Commented Apr 19, 2021 at 12:43

mkrieger1 · Accepted Answer · 2024-12-08 09:28:12Z

My solution is:

filling the nested list with records
sorting the list in the ascending order of scores
finding the lowest score
finding the names with the second lowest score - the second loop
sorting and printing the names in the alphabetical order

if __name__ == "__main__":
    # filling the nested list with records
    records = []
    for _ in range(int(input())):
        name = input()
        score = float(input())
        records.append([name, score])

    # sorting the list in the ascending order of scores
    sort_rec = sorted(records, key=lambda x: x[1])

    # this is the lowest score
    lowest_score = sort_rec[0][1]
    second_lowest_score = None
    names = []

    # looping over all the scores in sort_rec[1:]
    # beginning from the 1st (pythonic indexation)
    for item in sort_rec[1:]:
        # candidate value for the second lowest score
        cand_val = item[1]
        if cand_val > lowest_score:
            # checking if the candidate values is the same as the
            # second lowest score
            # of if the second lowest score is different from None
            if cand_val == second_lowest_score or second_lowest_score is None:
                names.append(item[0])
                second_lowest_score = cand_val
            else:
                break

    # sorting the names in the alphabetical order and printing
    [print(name) for name in sorted(names)]

entithat · Accepted Answer · 2021-04-22 10:44:53Z

0

The algorithm is:

Add all students with their marks to list reords
Sort list with unique marks (using set)
Filter list to get a student with the second min mark
Print name for each filtered student

Tested here:

if __name__ == '__main__':
    reords = []
    
    for _ in range(int(input())):
        name = input()
        score = float(input())
        reords.append([name, score])
 
    mark = sorted(set(map(lambda x: x[1], reords)))[1]
    for n, m in sorted(filter(lambda x: x[1] == mark, reords)):
        print(n)

edited Apr 22, 2021 at 10:44

answered Apr 19, 2021 at 12:43

entithat

3437 silver badges21 bronze badges

5 Comments

Amoungui Serge Over a year ago

You can test your code here: hackerrank.com/challenges/nested-list/problem

Amoungui Serge Over a year ago

can you publish your code please, juste to see?

entithat Over a year ago

@AmounguiSerge, you can see it in my answer :) However, pastebin.com/fVa5zb2x

Amoungui Serge Over a year ago

Cool, your code code work correctly. that's right. thank's for your help.

Amoungui Serge Over a year ago

I find you very experienced, how to stay in contact in order to exchange regularly. because I like your way of code, I would like to reach this level

Abhilash Mehta · Accepted Answer · 2022-11-09 20:58:14Z

0

student = []
marks = []
names = []
for _ in range(int(input())):
    name = input()
    score = float(input())
    student.append([name, score])

for item in student:
    marks.append(item[1])
marks = list(set(marks))
marks.sort()

for item in student:
    if marks[1] == item[1]:
        names.append(item[0])
names.sort()

for name in names:
    print(name)

answered Nov 9, 2022 at 20:58

Abhilash Mehta

11

1 Comment

Kyle F. Hartzenberg Over a year ago

Hi Abhilash, thanks for contributing an answer. It's good practice to include a brief explanation of your code in your answer so that future readers can quickly understand how it all works.

hello_mate · Accepted Answer · 2024-01-06 13:42:58Z

-1

nested_list=[]
for _ in range(int(input())):
    name = input()
    score = float(input())
    nested_list+=[[score, name]]
nested_list.sort()

for i in nested_list:
    if i[0]>nested_list[0][0]:
        second_lowest_grade= i[0]
        break;

student_names=[i[1] for i in nested_list if i[0]==second_lowest_grade]
student_names.sort()
for student_name in student_names:
    print(student_name)

answered Jan 6, 2024 at 13:42

hello_mate

11 bronze badge

Comments

mkrieger1 · Accepted Answer · 2024-12-08 08:09:32Z

-1

if __name__ == '__main__':
  student = []
    values = []
    names =[]
    for _ in range(int(input())):
        name = input()
        score = float(input())
        student.append([name, score])

    for item in student:
    values.append(item[1])
    values=list(set(values))
    values.sort()

    for item in student:
        if item[1] == values[1]:
            names.append(item[0])
            names.sort()

    for name in names:
        print(name)

edited Dec 8, 2024 at 8:09

mkrieger1

24.2k7 gold badges68 silver badges84 bronze badges

answered Aug 1, 2024 at 10:38

ayush

11 bronze badge

1 Comment

Community Over a year ago

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