import nltk
from nltk.tokenize import word_tokenize
from nltk.corpus import stopwords
from collections import Counter
import string

# nltk 리소스 다운로드
nltk.download('punkt')
nltk.download('stopwords')

def preprocess_text(text):
    # 소문자로 변환
    text = text.lower()
    
    # 문장 부호 제거
    text = text.translate(str.maketrans('', '', string.punctuation))
    
    # 단어 토큰화
    words = word_tokenize(text)
    
    # 불용어(stopwords) 제거
    stop_words = set(stopwords.words('english'))
    filtered_words = [word for word in words if word not in stop_words]
    
    return filtered_words

def analyze_frequency(words):
    # 단어 빈도 분석
    word_freq = Counter(words)
    return word_freq

# 샘플 텍스트
sample_text = """
Natural language processing (NLP) is a field of artificial intelligence (AI) that focuses on the interaction between computers and humans through natural language. The ultimate goal of NLP is to enable computers to understand, interpret, and generate human language in a way that is both meaningful and useful.
"""

# 텍스트 전처리
processed_words = preprocess_text(sample_text)

# 단어 빈도 분석
word_frequencies = analyze_frequency(processed_words)

print("단어 빈도 분석 결과:")
for word, freq in word_frequencies.items():
    print(f"{word}: {freq}")