How to create Nested List?

Question

n = int(input())
pythonName = []
for i in range(n):
    a = input("Enter the Name:")
    b = int(input("Enter the Score:"))
    pythonName.append(a)
    for j in range(n):
        pythonName[i].append(b)

print(pythonName)


------------Error------------

AttributeError                            Traceback (most recent call last)
<ipython-input-12-e737ad48a8fc> in <module>
      6     pythonName.append(a)
      7     for j in range(n):
----> 8         pythonName[i].append(b)
      9 
     10 print(pythonName)

AttributeError: 'str' object has no attribute 'append'

I am Creating a Nested List where I am trying to get from users. I want to desire output like this.

python students = [['Harry', 37.21], ['Berry', 37.21], ['Tina', 37.2], ['Akriti', 41], ['Harsh', 39]]

No, you are appending a string to the list, not another list. Try `pythonName.append([a, b])` — hpaulj, Feb 28 '20 at 22:40
Does this answer your question? [Python - Dynamic Nested List](https://stackoverflow.com/questions/3587215/python-dynamic-nested-list) — Sumsar1812, Feb 29 '20 at 02:13

score 1 · Answer 1 · answered Feb 28 '20 at 22:39

1

Your mistake is pythonName[i], because it is the nth iteration of your loop. In the error it is returning a string which you're trying to append to. List objects can be appended. String object can be concatenated.

answered Feb 28 '20 at 22:39

Vaidøtas I.

544
7
23

score 1 · Answer 2 · answered Feb 28 '20 at 23:57

I think you want is a dictionary where your key is the name and values are a list of scores

CODE:

n = int(input("How many Students?"))
pythonName = {}
for i in range(n):
    a = input("Enter the Name:")
    z = int(input("How many Scores?"))
    pythonName[a] = []
    for j in range(z):
        b = int(input(f"Enter the Score {j+1}:"))
        pythonName[a].append(b)

print(pythonName)

OUTPUT:

How many Students?2
Enter the Name:Errol
How many Scores?2
Enter the Score 1:1
Enter the Score 2:2
Enter the Name:Mark
How many Scores?3
Enter the Score 1:2
Enter the Score 2:1
Enter the Score 3:3
>>{'Errol': [1, 2], 'Mark': [2, 1, 3]}

But if you really want to use a list, you can try this instead:

n = int(input("How many Students?"))
pythonName = []
for i in range(n):
    a = input("Enter the Name:")
    z = int(input("How many Scores?"))
    student_name = []
    student_name.append(a)
    for j in range(z):
        b = int(input(f"Enter the Score {j+1}:"))
        student_name.append(b)
    pythonName.append(student_name)

print(pythonName)

OUTPUT:

How many Students?2
Enter the Name:Errol
How many Scores?2
Enter the Score 1:1
Enter the Score 2:2
Enter the Name:Mark
How many Scores?3
Enter the Score 1:2
Enter the Score 2:1
Enter the Score 3:3
>>[['Errol', 1, 2], ['Mark', 2, 1, 3]]

How to create Nested List?

2 Answers2