How I can accept nested dictionary from user in python

Question

I'm working on the simulation of nondeterministic finite automata (NFA), I want to let the user enter the state, alphabet and transaction function. For transaction functioning: variable t_state the user can enter multiple states for each alphabet like this

I used a nested dictionary

count_State = int(input("Please enter the number of NFA states..\n"))
states=list(map(int, input("Enter the states:-").strip().split()))         # NFA state set
count_alpha = int(input("Please enter the number of alphabets used\n"))
symbols=list(map(str, input("Enter the NFA alphabets:-").strip().split()))  # NFA alphabet
t_state = {}
for i in range(count_State):
    dict_name = input("Enter the state: ")
    t_state[dict_name] = {}
    for i in range(count_alpha):
        alphabet = input("Enter the alphabet: ")
        numVals = int(input("How many transition for that alphabet?\n"))
        transiction = []
        for value in range(numVals):
            transiction.append(input("Next transition\n"))
            dict_name[alphabet] = transiction
print(t_state)

I got this error : dict_name[alphabet] = transiction TypeError: 'str' object does not support item assignment

the expected output:

t_state = {
        '1': {
            'a': ['2','4'],
            'b': ['3']
        },
        '2': {
            'a': ['5'],
            'b': ['1']
        },
        '3': {
            'a': ['5'],
            'b': ['1']
        },
        '4': {
            'a': ['1'],
            'b': ['5']
        },
        '5': {
            '#': ['2'],
            'b': ['3']
        }
    }

Answer 1

This should do:

count_State = int(input("Please enter the number of NFA states..\n"))
states=list(map(int, input("Enter the states:-").strip().split()))         # NFA state set
count_alpha = int(input("Please enter the number of alphabets used\n"))
symbols=list(map(str, input("Enter the NFA alphabets:-").strip().split()))  # NFA alphabet
t_state = {}
for i in range(count_State):
    dict_name = input("Enter the state: ")
    t_state[dict_name] = {}
    for i in range(count_alpha):
        alphabet = input("Enter the alphabet: ")
        numVals = int(input("How many transition for that alphabet?\n"))
        transiction = []
        for value in range(numVals):
            transiction.append(input("Next transition\n"))
            t_state[dict_name][alphabet] = transiction
print(t_state)

Answer 2

d = {}
size = int(input("Enter the size of nested dictionary: "))
for i in range(size):
    d[i+1] = {}
    innerkey =list(map(str,input("Enter name of inner dict key: ").split()))
    innervalue=list(map(str,input("Enter value of inner dict: ").split()))
    d[i+1]["dict_name"] =innerkey
    d[i+1]["dict_value"] = innervalue
print(d)
input-Enter the size of nested dictionary: 3
Enter name of inner dict key: a
Enter value of inner dict: 23
Enter name of inner dict key: b
Enter value of inner dict: 45
Enter name of inner dict key: c
Enter value of inner dict: 45
output=
{1: {'dict_name': ['a'], 'dict_value': ['23']}, 2: {'dict_name': ['b'], 
'dict_value': ['45']}, 3: {'dict_name': ['c'], 'dict_value': ['45']}}

Answer 3

This could be a use-case for ast.literal_eval, it's like a "safe eval" to use in this kind of thing.
It's a built-in thing in both Python 3 and Python 2
You could do

from ast import literal_eval
t_state = dict()
s = input('Enter the state for 1: ') # raw_input in Python 2
# the user would enter a Python literal: { 'a': ['2','4'], 'b': ['3'] }
t_state['1'] = literal_eval(s)
print(repr(t_state)) # {'1': {'a': ['2', '4'], 'b': ['3']}}