User Input to Choose from Dictionary

[anelliaf]

Hello,

I'm looking to post a list of databases from a dictionary, then from the user input choose which database they want to connect.

import pprint, os

db_list = {
    1: {'name': 'TEST11C'},
    2: {'name': 'TEST12C'},
}
print("Databases:")
for x, y in db_list.items():
    print(x, y)

while True:
    print("Select a database: ")
    name = int(input())

    if name in db_list.keys():
        print("You have chosen: " + name)
    else:
        print('You chosen wrong!')

The user will select a database value based on the key integers of [1,2]. If they select out of that range they'll receive an error. If they select within the range it will take the value of the database.

Any help is appreciated.

Thanks,
Frank

[nilamo]

Doesn't what you already have do that?

[anelliaf]

No. When I enter a '1' for 'TEST11C' or '2' for the other one, I receive 'You chosen wrong!' when I should I receive the first part of the IF condition.

Databases:
1 {'name': 'TEST11C'}
2 {'name': 'TEST12C'}
Select a database:
1
You chosen wrong!
Select a database:

That was after I removed 'int' from input.

[buran]

Your code works for me if I correct the TypeError

Error:
Databases:
(1, {'name': 'TEST11C'})
(2, {'name': 'TEST12C'})
Select a database:
1
Traceback (most recent call last):
    print("You have chosen: " + name)
TypeError: cannot concatenate 'str' and 'int' objects
>>>

[anelliaf]

Got it, thx for that!

Here's my fix:

while True:
    print("Select a database: ")
    name = int(input())

    if name in db_list.keys():
        name = int(name)
        print("You have chosen: ", name, db_list[name])
    else:
        print('You chosen wrong!')

One other thing, how do I display only the database name and not the dictionary entry?

Output:

Select a database:
1
You have chosen: 1 {'name': 'TEST11C'}

Desired output:

Select a database:
1
You have chosen: TEST11C

[anelliaf]

Finished code:

db_list = {
    1: {'name': 'TEST11C'},
    2: {'name': 'TEST12C'},
}
print("Databases:")
for x, y in db_list.items():
    print(x, ':', db_list[x]['name'])

while True:
    print("\nSelect a database:")
    name = int(input())

    if x in db_list.keys():
        x = int(x)
        print("\nYou have chosen {0}".format(db_list[x]['name']))
    else:
        print('\nYou chosen wrong!')

Thanks for the help!

[buran]

A few comments:

• db_list - this variable name implies that it's a list, while in fact you have dict. You may decide to switch to list (see my next comment)
  
• dict is not ordered. In python3.6 the order of elements is preserved, but according to docs this is considered implementation detail and should not be relied upon. In other words the order in which you print dict items may be different from what you expect.
  
• line#13 - I expect you want to use name, not x. As it is now x is the last item from previous for loop, thus will always be present in db_list.keys(). Here keys() is not necessary, in always checks in dict.keys() by default
  
• line #15 - again you want to use name (i.e. the user input from line#11, not x
  

---

I just saw your other thread where you do use list, not dict
https://python-forum.io/Thread-Display-L...User-Input
I will not merge both threads as the other one is much older, but I post this link for completeness.

---

db_list = ['TEST11C', 'TEST12C']
print("Available Databases:")
for i, db_name in enumerate(db_list, start=1):
    print ('{}. {}'.format(i, db_name))
 
while True:
    try:
        selected = int(input('Select a database (1-{}): '.format(i)))
        db_name = db_list[selected-1]
        print('You have selected {}'.format(db_name))
        break
    except (ValueError, IndexError):
        print('This is not a valid selection. Please enter number between 1 and {}!'.format(i))

[anelliaf]

All your points taken into consideration. I'm unsure which direction to go in order to present the user a list of values. I started off with a list but was having trouble presenting the values. With a dictionary, it seems much simpler. I'm a beginner to programming so all the feedback you provided is much appreciated.

I updated my code with the following, per your advice:

databases = {
    1: {'name': 'TEST11C'},
    2: {'name': 'TEST12C'},
}

# Print databases listed in dictionary
print("Databases:")
for x, y in databases.items():
    print(x, ':', databases[x]['name'])

while True:
    print("\nSelect a database:")
    d_val = int(input())

    if d_val in databases.keys():
        d_val = int(d_val)
        print("\nYou have chosen {0}".format(databases[d_val]['name']))
    else:
        print('\nYou chosen wrong!')

[buran]

I updated my post #7 with an example

[anelliaf]

Awesome, got it! Thanks a lot for the example and advice.