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Update main.py
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from contextlib import asynccontextmanager
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel, ValidationError
from fastapi.encoders import jsonable_encoder
# TEXT PREPROCESSING
# --------------------------------------------------------------------
import re
import string
import nltk
nltk.download('punkt')
nltk.download('wordnet')
nltk.download('omw-1.4')
from nltk.stem import WordNetLemmatizer
# Function to remove URLs from text
def remove_urls(text):
return re.sub(r'http[s]?://\S+', '', text)
# Function to remove punctuations from text
def remove_punctuation(text):
regular_punct = string.punctuation
return str(re.sub(r'['+regular_punct+']', '', str(text)))
# Function to convert the text into lower case
def lower_case(text):
return text.lower()
# Function to lemmatize text
def lemmatize(text):
wordnet_lemmatizer = WordNetLemmatizer()
tokens = nltk.word_tokenize(text)
lemma_txt = ''
for w in tokens:
lemma_txt = lemma_txt + wordnet_lemmatizer.lemmatize(w) + ' '
return lemma_txt
def preprocess_text(text):
# Preprocess the input text
text = remove_urls(text)
text = remove_punctuation(text)
text = lower_case(text)
text = lemmatize(text)
return text
# Load the model using FastAPI lifespan event so that teh model is loaded at the beginning for efficiency
@asynccontextmanager
async def lifespan(app: FastAPI):
# Load the model from HuggingFace transformers library
from transformers import pipeline
global sentiment_task
sentiment_task = pipeline("sentiment-analysis", model="cardiffnlp/twitter-roberta-base-sentiment-latest", tokenizer="cardiffnlp/twitter-roberta-base-sentiment-latest")
yield
# Clean up the model and release the resources
del sentiment_task
description = """
## Text Classification API
This app shows the sentiment of the text (positive, negative, or neutral).
Check out the docs for the `/analyze/{text}` endpoint below to try it out!
"""
# Initialize the FastAPI app
app = FastAPI(lifespan=lifespan, docs_url="/", description=description)
# Define the input data model
class TextInput(BaseModel):
text: str
# Define the welcome endpoint
@app.get('/')
async def welcome():
# Redirect to the Swagger UI page
return RedirectResponse(url="/docs")
# Validate input text length
MAX_TEXT_LENGTH = 1000
# Define the sentiment analysis endpoint
@app.post('/analyze/{text}')
async def classify_text(text_input:TextInput):
try:
# Convert input data to JSON serializable dictionary
text_input_dict = jsonable_encoder(text_input)
# Validate input data using Pydantic model
text_data = TextInput(**text_input_dict) # Convert to Pydantic model
# Validate input text length
if len(text_input.text) > MAX_TEXT_LENGTH:
raise HTTPException(status_code=400, detail="Text length exceeds maximum allowed length")
elif len(text_input.text) == 0:
raise HTTPException(status_code=400, detail="Text cannot be empty")
except ValidationError as e:
# Handle validation error
raise HTTPException(status_code=422, detail=str(e))
try:
# Perform text classification
return sentiment_task(preprocess_text(text_input.text))
except ValueError as ve:
# Handle value error
raise HTTPException(status_code=400, detail=str(ve))
except Exception as e:
# Handle other server errors
raise HTTPException(status_code=500, detail=str(e))