Mapping values from a dictionary's list to a string in Python

Question

I am working on some sentence formation like this:

sentence = "PERSON is ADJECTIVE"
dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"]}

I would now need all possible combinations to form this sentence from the dictionary, like:

Alice is cute
Alice is intelligent
Bob is cute
Bob is intelligent
Carol is cute
Carol is intelligent

The above use case was relatively simple, and it was done with the following code

dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"]}

for i in dictionary["PERSON"]:
    for j in dictionary["ADJECTIVE"]:
        print(f"{i} is {j}")

But can we also make this scale up for longer sentences?

Example:

sentence = "PERSON is ADJECTIVE and is from COUNTRY" 
dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"], "COUNTRY": ["USA", "Japan", "China", "India"]}

This should again provide all possible combinations like:

Alice is cute and is from USA
Alice is intelligent and is from USA
.
.
.
.
Carol is intelligent and is from India

I tried to use https://www.pythonpool.com/python-permutations/ , but the sentence are all are mixed up - but how can we make a few words fixed, like in this example the words "and is from" is fixed

Essentially if any key in the dictionary is equal to the word in the string, then the word should be replaced by the list of values from the dictionary.

Any thoughts would be really helpful.

If you need help getting started, I would look at what itertools.product(*dictionary.values()) gives you, — JonSG
– JonSG, Commented Dec 12, 2021 at 17:32
You might want to convert your sentence into something that str.format() knows how to handle so you don't have to do the replace stuff yourself. — Samwise
– Samwise, Commented Dec 12, 2021 at 17:52

JonSG · Accepted Answer · 2021-12-21 16:45:44Z

2

I would base my answer off of two building blocks itertools.product and zip.

itertools.product will allow us to get the various combinations of our dictionary list values

zip with the original keys and the combinations above will allow us to create a list of tuples that we can use with replace.

import itertools

sentence = "PERSON is ADJECTIVE and is from COUNTRY"
dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"], "COUNTRY": ["USA", "Japan", "China", "India"]}

keys = dictionary.keys()
for values in itertools.product(*dictionary.values()):
    new_sentence = sentence
    for tpl in zip(keys, values):
        new_sentence = new_sentence.replace(*tpl)
    print(new_sentence)

IF you happen to have the ability to control the "sentence" template, and you can do:

sentence = "{PERSON} is {ADJECTIVE} and is from {COUNTRY}"

Then you can simplify this to:

sentence = "{PERSON} is {ADJECTIVE} and is from {COUNTRY}"
dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"], "COUNTRY": ["USA", "Japan", "China", "India"]}

keys = dictionary.keys()
for values in itertools.product(*dictionary.values()):
    new_sentence = sentence.format(**dict(zip(keys, values)))
    print(new_sentence)

both should give you the results like:

Alice is cute and is from USA
Alice is cute and is from Japan
...
Carol is intelligent and is from China
Carol is intelligent and is from India

Note that the order of appearance in the template is not important and both solutions should work with a template of:

sentence = "PERSON is from COUNTRY and is ADJECTIVE"

or in case 2

sentence = "{PERSON} is from {COUNTRY} and is {ADJECTIVE}"

Followup:

What happens if there is a chance that the dictionary contains items that are not in the sentence template? At the moment, that is not ideal as the way the sentences are generated with product() assumes that all keys are and we currently would generate duplicates.

The easiest fix for that would be to just ensure that the dictionary only has keys of interest...

In the first case this might do that.

dictionary = {key: value for key, value in dictionary.items() if key in sentence}

or in the second case:

dictionary = {key: value for key, value in dictionary.items() if f"{{{key}}}" in sentence}

edited Dec 21, 2021 at 16:45

answered Dec 12, 2021 at 18:25

JonSG

13.6k2 gold badges32 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Dragon Z Over a year ago

thank you so much, this works perfectly well, but there are duplicates if the sentence does not contain all the keys in the dictionary

sentence = "PERSON is ADJECTIVE" dictionary = {"PERSON": ["Alice", "Bob", "Carol"], "ADJECTIVE": ["cute", "intelligent"], "COUNTRY": ["USA", "Japan", "China", "India"]}

Any thoughts on how can we avoid this, without using sets for removing duplicates. I want to maintain the order, so I don't need sets to remove the duplicates.

JonSG Over a year ago

That is an interesting twist. Let me update the answer...

Dragon Z Over a year ago

Thank you so much @jonsg for the follow up solution. This is a fast, simple and a brilliant solution!! I tried a sentence that had "PERSON is ADJECTIVE and ADJECTIVE" in the intention to get combinations like "Alice is cute and intelligent", but since we are using replace, the output gives "Alice is cute and cute", "Alice is intelligent and intelligent". This sentence is ok, but can there be a possibility where we could get combinations like "Alice is cute and intelligent"? Any suggestions would be of a great help and I totally appreciate it. Thanks!

user7864386 · Accepted Answer · 2021-12-12 17:53:11Z

1

You can first replace the dictionary keys in sentence to {} so that you can easily format a string in loop. Then you can use itertools.product to create the Cartesian product of dictionary.values(), so you can simply loop over it to create your desired sentences.

from itertools import product
sentence = ' '.join([('{}' if w in dictionary else w) for w in sentence.split()])
mapped_sentences_generator = (sentence.format(*tple) for tple in product(*dictionary.values()))
for s in mapped_sentences_generator:
    print(s)

Output:

Alice is cute and is from USA
Alice is cute and is from Japan
Alice is cute and is from China
Alice is cute and is from India
Alice is intelligent and is from USA
Alice is intelligent and is from Japan
Alice is intelligent and is from China
Alice is intelligent and is from India
Bob is cute and is from USA
Bob is cute and is from Japan
Bob is cute and is from China
Bob is cute and is from India
Bob is intelligent and is from USA
Bob is intelligent and is from Japan
Bob is intelligent and is from China
Bob is intelligent and is from India
Carol is cute and is from USA
Carol is cute and is from Japan
Carol is cute and is from China
Carol is cute and is from India
Carol is intelligent and is from USA
Carol is intelligent and is from Japan
Carol is intelligent and is from China
Carol is intelligent and is from India

Note that this works for Python >3.6 because it assumes the dictionary insertion order is maintained. For older Python, must use collections.OrderedDict rather than dict.

answered Dec 12, 2021 at 17:53

user7864386

1 Comment

JonSG Over a year ago

While this works in this specific case, it is a little fragile in that it will fail if the sentence is changed so that it does not align with the order of the keys. For example sentence = "PERSON is from COUNTRY and is ADJECTIVE" will give one Carol is from cute and is USA

Collectives™ on Stack Overflow

Mapping values from a dictionary's list to a string in Python

2 Answers 2

3 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related