Function to see if i can generate phrase from characters string

Question

I am trying to write a function that checks if I can generate the required word/phrase using the characters provided. The phrase created can contain any characters including special characters, capital letters, numbers, and spaces.

I can generate the phrase if the frequency of unique characters in the characters string is equal or greater than the frequency in the phrase.

What I tried to do was use a counter and then compare the dictionaries that it produced but not sure how to find if the characters in the character string are more in frequency than in the phrase.

This is my code:

from collections import Counter

def generate_phrase(characters, phrase):
  new_characters = characters.lower()
  new_phrase = phrase.lower()
  a = Counter(new_characters)
  b = Counter(new_phrase)
  if a == b:
    return True 
  else:
    return False

This example should produce false, as there are less characters in the character string than the phrase

characters = "cbacba"
phrase = "aabbccc"

generate_phrase(characters, phrase)

Ouput:
False

This example should produce True as although it has other letters in it, that are not in the phrase. It does contain all characters of the phrase and the right frequency of them.

characters = "Magiciansktb!"
phrase = "m!aagsnici"

generate_phrase(characters, phrase)

Ideal Ouput:
True

My current code output:
False

Asked By: Jennifer

||

Source

Answer 1

Use all() to test if every count from characters is at least the count of the corresponding character in phrase.

def generate_phrase(characters, phrase):
    new_characters = characters.lower()
    new_phrase = phrase.lower()
    char_counts = Counter(new_characters)
    phrase_counts = Counter(new_phrase)
    return all(char_counts.get(char, 0) >= count for char, count in phrase_counts.items())

Answered By: Barmar

Answer 2

Alternatively, you can try this code to see if it helps you:

It tries to handle some edge cases here, if errors caught earlier, and it bails out right away, will not go further process. Just make a note of it.


def generate_phrase(letters: str, phrase: str) -> bool:
    phrase_cnt = Counter(phrase.lower())
    chars_cnt  = Counter(letters.lower())

    if not phrase_cnt and not chars_cnt:      # both are empty?
        return True
        
    #if not letters:  return False
        
    if len(phrase) >  len(letters):       # not enought letters?
        return False


    for ch, cnt in phrase_cnt.items():
     
        if ch in chars_cnt and cnt <= chars_cnt.get(ch):
            continue
        else:
            return False 
        
    return True


if __name__ == '__main__':
    characters = "cbacba"
    phrase = "aabbccc"

    print(generate_phrase(characters, phrase))          # False

    print(generate_phrase('footeatips', 'tattoo'))      # False

    print(generate_phrase('gooseteatipstim', 'tattoo'))  # True

    characters2 = "Magiciansktb!"
    phrase2 = "m!aagsnici"
    print(generate_phrase(characters2, phrase2))   # True

Answered By: Daniel Hao

Function to see if i can generate phrase from characters string

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