How to read a dictionary from this text file?

Question

I am still new to python and I am playing around with saving data to text files. My problem is that when I try to access a dictionary it comes up with this error TypeError: string indices must be integers but I don't know how to convert them.

This is what's inside my file:

Student 1/:{ "Topic 1" : 0,"Topic 2" : 0,"Topic 3" : 0,"Topic 4" : 4}
Student 2/:{ "Topic 1" : 1,"Topic 2" : 2,"Topic 3" : 0,"Topic 4" : 0}
Student 3/:{ "Topic 1" : 1,"Topic 2" : 0,"Topic 3" : 0,"Topic 4" : 1}

This is my code:

import ast #I thought this would fix the problem

def main():
  data = {}
  with open("test.txt") as f:
    for line in f:
        content = line.rstrip('\n').split('/:')
        data[content[0]] = ast.literal_eval(content[1])
  f.close()
  print(data["Student 1"["Topic 1"]]) # works if I only do data[Student 1]

main()

If there is a more efficient way of storing the data?

Answer 1

I'd suggest using JSON to write the data out to a text file https://docs.python.org/3/library/json.html

You can use the json.dumps method to create JSON data that can be written to a file and use the json.loads method to convert the text from the file back in to a dictionary

Answer 2

Well since your question asks for "a more efficient way of storing the data" I'm going to say yes!

https://docs.python.org/3/library/shelve.html

Shelve is a great tool to store dictionaries persistently and change / edit the dictionary whenever. I'm currently using it for a discord bot project I'm working on and so far it's been great.

Here is some usage tips to get your started (pulled directly from the page I linked).

import shelve

d = shelve.open(filename)  # open -- file may get suffix added by low-level
                           # library

d[key] = data              # store data at key (overwrites old data if
                           # using an existing key)
data = d[key]              # retrieve a COPY of data at key (raise KeyError
                           # if no such key)
del d[key]                 # delete data stored at key (raises KeyError
                           # if no such key)

flag = key in d            # true if the key exists
klist = list(d.keys())     # a list of all existing keys (slow!)

# as d was opened WITHOUT writeback=True, beware:
d['xx'] = [0, 1, 2]        # this works as expected, but...
d['xx'].append(3)          # *this doesn't!* -- d['xx'] is STILL [0, 1, 2]!

# having opened d without writeback=True, you need to code carefully:
temp = d['xx']             # extracts the copy
temp.append(5)             # mutates the copy
d['xx'] = temp             # stores the copy right back, to persist it

# or, d=shelve.open(filename,writeback=True) would let you just code
# d['xx'].append(5) and have it work as expected, BUT it would also
# consume more memory and make the d.close() operation slower.

d.close()                  # close it