update dictionary with dynamic keys and values in python

Question

I have a dictionary and I want to insert keys and values dynamically but I didn't manage to do it. The problem is that when I use the update method it doesn't add a pair but it deletes the previous values so I have only the last value when printing the dictionary here is my code

i = 0 for o in iterload(f):     i=i+1     mydic = {i : o["name"]}     mydic.update({i : o["name"]})     for k, v in mydic.items():         print(k,v)  print(mydic) 

f is a file that i'm parsing with python code as a result I get

{3: 'toto'} 

which is the last element. is there a solution to have all the elements in my dictionary

Thanks in advance

I have another question

Now I need to chek if an input value equals a key from my dictionary and if so I need to get the value of this key to continue parsing the file and get other informations.

Here is my code :

f = open('myfile','r') nb_name = input("\nChoose the number of the name :")  for o in iterload(f):     if o["name"] == mydic[nb_name]:          ... 

I get a keyError

Traceback (most recent call last):   File ".../test.py", line 37, in <module>             if o["name"] == mydic[nb_name]:  KeyError: '1' 

I don't understand the problem

Answer 1

Remove the following line:

    mydic = {i : o["name"]} 

and add the following before your loop:

mydic = {} 

Otherwise you're creating a brand new one-element dictionary on every iteration.

Also, the following:

mydic.update({i : o["name"]}) 

is more concisely written as

mydic[i] = o["name"] 

Finally, note that the entire loop can be rewritten as a dictionary comprehension:

mydic = {i+1:o["name"] for i,o in enumerate(iterload(f))} 

Answer 2

You could use len() to insert the value:

#!/usr/bin/python  queue = {}  queue[len(queue)] = {'name_first': 'Jon', 'name_last': 'Doe'} queue[len(queue)] = {'name_first': 'Jane', 'name_last': 'Doe'} queue[len(queue)] = {'name_first': 'J', 'name_last': 'Doe'}  print queue