How to check if all values in a dictionary exist in a list?

Question

So I have a dictionary of user preferences that I'd like to check and see if ALL of the dictionary values exist in a list.

For example, I have a dictionary like:

dct = { 'key1' : 'value1', 'key2' : 'value2'}

And I have a list like so:

lst = ['list1', 'list2', 'list3', 'list4']

I'm trying to check if all of the values in the dictionary exist in the list.

How do I do this?

EDIT to be more specific:

My dictionary is

userprefs = {'RON' : 'PHX'}

My list is

poss_matches = [['misc0', 'misc1', 'misc2', 'misc3', 'misc4', 'misc5', 'misc6', 'misc7', 'PHX-']]

However, if I use something like:

    for seq in poss_matches:
        for p in userprefs:
            if userprefs[p] in seq:
                matches.append(seq)

I get an empty list for matches.

Possible duplicate of [Return None if Dictionary key is not available](https://stackoverflow.com/questions/6130768/return-none-if-dictionary-key-is-not-available) — DollarAkshay, Jan 04 '19 at 10:54
@cph_sto: they are not keywords, but names of built-ins, keywords are `lambda`, `return`, `def`, etc. and using them as objects names will end up in `SyntaxError` — Azat Ibrakov, Jan 04 '19 at 10:59
Sorry, I just used those variable names for example, I'm not actually using the names of built-ins. — Brandon Himes, Jan 04 '19 at 11:12

anurag0510 · Answer 1 · 2019-01-04T10:58:12.000

1

You could try this :

def checker():
    for value in dct.values():
        if value in lst:
            continue
        else:
            return False
    return True

dct = { 'key1' : 'list1', 'key2' : 'list1'}
lst = ['list1', 'list2', 'list3', 'list4']
print(checker())

By this you will be fetching values from dictionary in value variable and checking whether it's present in list.

edited Jan 04 '19 at 10:58

answered Jan 04 '19 at 10:51

anurag0510

763
1
8
17

cph_sto · Answer 2 · 2019-01-04T11:16:40.010

Method 1:

myDict = { 'key1' : 'value1', 'key2' : 'value2'}
values_myDict = myDict.values() # Outputs all the values of a dictionary in a list.
values_myDict
    ['value1', 'value2']

# Use set() - In case myList has all the values of the dictionary, we will get True, else False
myList = ['list1', 'list2', 'list3', 'list4', 'value1', 'value2']
bool_value = set(values_myDict) < set(myList)
bool_value
    True     # because both 'value1' & 'value2' are presnt.

myList = ['list1', 'list2', 'list3', 'list4', 'value1',]
bool_value = set(values_myDict) < set(myList)
bool_value
    False    # because 'value2' is not present.

Method 2: As suggested by Jon Clements. A more concise and succinct one.

myDict = { 'key1' : 'value1', 'key2' : 'value2'}
myList = ['list1', 'list2', 'list3', 'list4', 'value1', 'value2']
bool_value = set(myDict.values()).issubset(myList)
bool_value
    True

myList = ['list1', 'list2', 'list3', 'list4', 'value1']
bool_value = set(myDict.values()).issubset(myList)
bool_value 
    False

Many thanks Jon for your remarks. I made an additional update. — cph_sto, Jan 04 '19 at 11:17

Sociopath · Answer 3 · 2019-01-04T12:42:35.167

1

You need all() with for loop

dct = { 'key1' : 'list1', 'key2' : 'list2','k3':'list3','k4':'list4'}
lst = ['list1', 'list2', 'list3', 'list4']

all(x in lst for x in dct.values())

Output:

True

edited Jan 04 '19 at 12:42

answered Jan 04 '19 at 11:01

Sociopath

13,068
19
47
75

I'm trying to check if all of the values in the dictionary exist in the list - `all(x in lst for x in dct.values())` – cph_sto Jan 04 '19 at 12:31

score 1 · Answer 4 · answered Jan 04 '19 at 11:18

1

You can try below approach

dct = { 'key1' : 'list1', 'key2' : 'list3'}
lst = ['list1', 'list2', 'list3', 'list4']
flag='N'
for each in dct:
   if dct[each] in lst:
      flag='Y'
   else:
      flag='N'
print (flag)

answered Jan 04 '19 at 11:18

Akshay Sapra

436
5
22

I don't understand why would anyone downvote it.. it's not that a bad approach.. lol.. – Akshay Sapra Aug 24 '19 at 05:07

How to check if all values in a dictionary exist in a list?

4 Answers4