fastapi connection using Python requests

Question

I have a fast api for a simple ML model. THE post request for API is

@app.post('/predict')   
def predict_species(data: str):
    data_new = np.array([data])

    prob = lr_tfidf.predict_proba(data_new).max()
    pred = lr_tfidf.predict(data_new)
    return {'Movie Review': data,
             'Predictions':f'{pred[0]}',
            'Surity for Review': f'{prob}'}

Now, when I try to connect it using python requests module, it is giving me error.

import requests

review = {'data': 'THIS IS A POSITIVE MOVIE'}
resp = requests.post("http://localhost:8000/predict", json=review)   

print(resp.content)

The content is

b'{"detail":[{"loc":["query","data"],"msg":"field required","type":"value_error.missing"}]}'

The Terminal Error Message is

INFO:     127.0.0.1:45730 - "POST /predict HTTP/1.1" 422 Unprocessable Entity

How to solve this?

score 1 · Answer 1 · answered Mar 14 '21 at 10:46

1

FastAPI expects a query parameter like this, but you are sending a json in the request's body.

This expects a query parameter

@app.post('/predict')   
def predict_species(data: str):

You need to use Body() function or a Pydantic model.

from fastapi import Body

@app.post('/predict')   
def predict_species(data: str = Body(...)):
    ...

answered Mar 14 '21 at 10:46

Yagiz Degirmenci

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3

It's also well explained in the docs. I guess OP didn't go through the docs first... https://fastapi.tiangolo.com/tutorial/body-multiple-params/#singular-values-in-body – lsabi Mar 14 '21 at 11:09
How should I send a query parameter? – Ahmad Anis Mar 14 '21 at 12:45
Check my another [answer](https://stackoverflow.com/a/64936353/13161155) to see the difference between them. – Yagiz Degirmenci Mar 14 '21 at 12:54

fastapi connection using Python requests

1 Answers1