How to pass string and multiple files using FastAPI and Python requests?
Question:
I am using the following FastAPI endpoint that accepts multiple files:
from fastapi import Request, FastAPI, File, UploadFile
from typing import List
import uvicorn
app = FastAPI()
@app.post("/multiplefiles")
async def _file_upload(keywords, files: List[UploadFile] = File(...)): #create_file
return {"len_files": keywords}
I would like to first input the keywords parameter, then the list of files, but I cannot find a way to perform a valid post request:
import requests
files = (("keywords", "key1"),
[
('files', open('filesfile1.pdf', 'rb')),
('files', open('filesfile2.pdf', 'rb'))
]
)
response = requests.post('http://127.0.0.1:3000/multiplefiles', files=files)
print(response.json())
If I only upload the files as a list of tuple work, but I do not know how to pass in the keywords parameter.
Answers:
Option 1 – Define query parameter as str
In the way the keywords parameter is defined in your endpoint is expected to be a query parameter. If you expect it to be a single string value, you can define it using str as follows:
Server side:
@app.post("/")
def upload(keywords: str, files: List[UploadFile] = File(...)):
return {"keywords": keywords}
Since it is expected as query parameter, you should use the params argument in Python requests, in order to pass query parameters, as described here. Example:
Client side:
url = 'http://127.0.0.1:8000/'
data = {'keywords': 'key1'}
r = requests.post(url, files=files, params=data)
print(r.json())
You could also pass it directly to the URL instead:
url = 'http://127.0.0.1:8000?keywords=key1'
Option 2 – Define query parameter as List
If you are sending a list of keywords, you have to declare the keywords query parameter with a type of List (or list in Python 3.9+), and define it explicitly with Query, so that it can receive a list of values, or in other words, to receive multiple values—see related answers here, here and here (for arbitrary query parameters see this and this). Example:
Server side:
from fastapi import Query
@app.post("/")
def upload(keywords: List[str] = Query(...), files: List[UploadFile] = File(...)):
return {"keywords": keywords}
Client side:
url = 'http://127.0.0.1:8000/'
data = {'keywords': ['key1', 'key2']}
r = requests.post(url, files=files, params=data)
print(r.json())
If you would like to add the list of keywords to the URL’s query string yourself, it should then look like this:
url = 'http://127.0.0.1:8000?keywords=key1&keywords=key2'
Option 3 – Use Form parameters
If you would like to use Form parameters instead to pass additional data along with files, please have a look at this answer.
I am using the following FastAPI endpoint that accepts multiple files:
from fastapi import Request, FastAPI, File, UploadFile
from typing import List
import uvicorn
app = FastAPI()
@app.post("/multiplefiles")
async def _file_upload(keywords, files: List[UploadFile] = File(...)): #create_file
return {"len_files": keywords}
I would like to first input the keywords parameter, then the list of files, but I cannot find a way to perform a valid post request:
import requests
files = (("keywords", "key1"),
[
('files', open('filesfile1.pdf', 'rb')),
('files', open('filesfile2.pdf', 'rb'))
]
)
response = requests.post('http://127.0.0.1:3000/multiplefiles', files=files)
print(response.json())
If I only upload the files as a list of tuple work, but I do not know how to pass in the keywords parameter.
Option 1 – Define query parameter as str
In the way the keywords parameter is defined in your endpoint is expected to be a query parameter. If you expect it to be a single string value, you can define it using str as follows:
Server side:
@app.post("/")
def upload(keywords: str, files: List[UploadFile] = File(...)):
return {"keywords": keywords}
Since it is expected as query parameter, you should use the params argument in Python requests, in order to pass query parameters, as described here. Example:
Client side:
url = 'http://127.0.0.1:8000/'
data = {'keywords': 'key1'}
r = requests.post(url, files=files, params=data)
print(r.json())
You could also pass it directly to the URL instead:
url = 'http://127.0.0.1:8000?keywords=key1'
Option 2 – Define query parameter as List
If you are sending a list of keywords, you have to declare the keywords query parameter with a type of List (or list in Python 3.9+), and define it explicitly with Query, so that it can receive a list of values, or in other words, to receive multiple values—see related answers here, here and here (for arbitrary query parameters see this and this). Example:
Server side:
from fastapi import Query
@app.post("/")
def upload(keywords: List[str] = Query(...), files: List[UploadFile] = File(...)):
return {"keywords": keywords}
Client side:
url = 'http://127.0.0.1:8000/'
data = {'keywords': ['key1', 'key2']}
r = requests.post(url, files=files, params=data)
print(r.json())
If you would like to add the list of keywords to the URL’s query string yourself, it should then look like this:
url = 'http://127.0.0.1:8000?keywords=key1&keywords=key2'
Option 3 – Use Form parameters
If you would like to use Form parameters instead to pass additional data along with files, please have a look at this answer.