how to check if a key and value from one dictionary is in another?

Question

I'm having trouble searching if a key and corresponding value from one dictionary (stock) is in another dictionary (basket)

this is the error I receive:

File "C:/Users/mbbx2wc3/.spyder2-py3/temp.py", line 35, in <module>
  if stock['10005'] in basket:

TypeError: unhashable type: 'dict'

And this is my code if you want to have a look. I have tried is stock[key] in basket. but this gives an error and I cannot think of an alternative to try.

Many thanks

        stock = {
            '10005' : {
                    'name' : 'Conference Pears Loose',
                    'price' : 2.00,
                    'unit' : 'kg', 
                    'promotion' : None,
                    'group' : None,
                    'amount' : 1.550
             },
             '10013' : {
                    'name' : 'Emmental Slices 250G',
                    'price' : 1.75,
                    'unit' : 'pieces', 
                    'promotion' : 'get2pay1',
                    'group' : None,
                    'amount' : 9
             },
             '10015' : { 
                    'name' : 'Diced Beef 400G', 
                    'price' : 4.50,
                    'unit' : 'pieces', 
                    'promotion': 'get4pay3',
                    'group' : 4,
                    'amount' : 14
            }}

        basket = {}

        if stock['10005'] in basket:
            print("yay")
        else:
            print("noo")

`in` tests key membership for dicts. Try `if stock['10005'] in basket.values()` as a starting point. — Alex Hall, Apr 28 '16 at 12:57

score 1 · Answer 1 · answered Apr 28 '16 at 13:05

1

Just use the key...

if '10005' in basket:
    print("it's in basket")
elif '10005' in stock:
    print("it's in stock")
else:
    print("it's nowhere")

answered Apr 28 '16 at 13:05

alec_djinn

10,104
8
46
71

score 1 · Answer 2 · answered Apr 28 '16 at 13:05

You are looking to see if the value of stock['10005'], which is some large dict, is also a key in basket.

https://docs.python.org/2/library/stdtypes.html#typesmapping

A dictionary’s keys are almost arbitrary values. Values that are not hashable, that is, values containing lists, dictionaries or other mutable types (that are compared by value rather than by object identity) may not be used as keys.

I think perhaps you want to see if '10005' in basket

sehrob · Answer 3 · 2016-04-28T13:13:12.950

0

You can try something like this:

key = 'a key your are testing'
if basket.get(key, false) == stock[key]:
    print('yes')
else:
    print('no')

edited Apr 28 '16 at 13:13

answered Apr 28 '16 at 13:07

sehrob

1,034
12
24

score 0 · Answer 4 · edited May 23 '17 at 12:23

First of all, you can't test if something contains a dictionary. The error message TypeError: unhashable type: 'dict' is basically telling you that; there are some details about that here.

You're probably going to need a two step process:

Is the given key in the target dictionary?
Does the corresponding value match?

For example:

if '10005' in basket and basket['10005'] == stock['10005']:
    print "Yup"
else:
    print "Nope"

score 0 · Answer 5 · answered Apr 28 '16 at 13:16

import json 
stock = {
        '10005' : {
                'name' : 'Conference Pears Loose',
                'price' : 2.00,
                'unit' : 'kg', 
                'promotion' : None,
                'group' : None,
                'amount' : 1.550
         },
         '10013' : {
                'name' : 'Emmental Slices 250G',
                'price' : 1.75,
                'unit' : 'pieces', 
                'promotion' : 'get2pay1',
                'group' : None,
                'amount' : 9
         },
         '10015' : { 
                'name' : 'Diced Beef 400G', 
                'price' : 4.50,
                'unit' : 'pieces', 
                'promotion': 'get4pay3',
                'group' : 4,
                'amount' : 14
        }}

basket = {}
for item in stock.keys():
    if item in basket.keys():
        print("This key " + item + " is in basket") 
    else:
        print("This key " + item + " is not in basket")

for item in stock.values():
    if item in basket.values():
        print("This value " + json.dumps(item) + " is in basket") 
    else:
        print("This value " + json.dumps(item) + " is not in basket")

how to check if a key and value from one dictionary is in another?

5 Answers5