Sentiment

This is a WSGI web application that analyses the sentiment of short text strings.

It has just one simple endpoint, /sentiment, that accepts a POST request with a text/plain payload of text to analyze. It returns a JSON response with a score field containing a floating point number between -1 and 1.

Quick Start

1. install Python 3.10
2. clone this repository
3. install the dependencies with pipenv install
4. modify the settings.json file to include your third-party API credentials (optional)
5. run the server with pipenv run python -m flask run

Authentication

The service is protected by a very simple Bearer authentication scheme. (https://swagger.io/docs/specification/authentication/bearer-authentication/) For testing, valid tokens can be configured in the settings.json file. For production, you will need to implement your method of acquiring and validating tokens.

Fallback

The service primarily uses a third-party API to perform sentiment analysis. However, when that API is unavailable, the service falls back to a local language model.

Configuration

The service can be configured using the settings.json file.

client

The client section specifies the third-party API to use for sentiment analysis.

It has the following properties:

• class - The name of a class that implements the SentimentClassifier interface. Currently implemented classes are TwinWordClient and ConnexunClient.
• url - The URL of the third-party API sentiment analysis route.
• headers - A dictionary of headers to include in the request to the third-party API. These typically specify authentication and content type.
• method - "get" or "post"
• timeout - The number of seconds to wait for a response from the third-party API.

model

The model section has one property: The name field specifies the fully-qualified name of a Huggingface model to use locally when the third-party API is unavailable.

fallback

The fallback section lets you configure the fallback behavior:

• retry_after - The number of seconds to wait before retrying the third-party API after a failure.
• increase_retry - The number of seconds to increase the wait time by after each failure.
• max_wait - The maximum number of seconds to which the timeout can increase.

logging

The optional logging section lets you configure the logging behavior.

tokens

The optional tokens section lets you configure authentication tokens for testing. For example, the following tokens:

"tokens": [
    {"client_id": "test", "access_token": "just for testing!"}
  ],

will allow a request with the header Authorization "Bearer test" to access the service.

test_csv

The optional test_csv path lets you configure a CSV file to use for testing. Point it to a CSV file with a text column, such as the twitter-airline-sentiment dataset before running the unit tests.

Example

Here is an example of a request and response:

PowerShell

Invoke-WebRequest -Uri http://localhost:8000/sentiment -Method Post -Body "yes that's AWESOME" -ContentType "text/plain" -Headers @{'Authorization'= 'bearer test'}

bash

curl -X POST http://localhost:8000/sentiment --data "yes that's AWESOME" -H "Content-Type: text/plain" -H 'Authorization: "Bearer test"'

Response (200 OK)

{"score":0.9949,"text":"yes that's AWESOME"}