I have the following endpoint in my FastAPI server:
@app.post("/submit")
async def submit(file1: List[UploadFile] = File(...), file2: List[UploadFile] = File(...), file3: List[UploadFile] = File(...)):
# do something
return 'hello'
It works as expected if I use Swagger UI. However, I cannot figure out how to send a POST request to this endpoint using Python requests module. Here is what I've tried:
import requests
headers = {
'accept': 'application/json',
'Content-Type': 'multipart/form-data',
}
files = [
('file1', open('file1.zip', 'rb')),
('file2', open('file2.txt', 'rb')),
('file3', open('file3.rar', 'rb')),
]
response = requests.post('http://localhost:8000/submit', headers=headers, files=files)
print(response.text)
But I am getting an error:
{"detail":"There was an error parsing the body"}
You should either define each file as a separate parameter in the endpoint, e.g., file1: UploadFile = File(...), file2: UploadFile = File(...), etc. (without using List), or, preferably, define a List of files using files: List[UploadFile] = File(...), as shown below (the below can be used to return the filenames of all uploaded files).
@app.post("/submit")
async def submitUPP(files: List[UploadFile] = File(...)):
# do something
return {"Uploaded Files:": [file.filename for file in files]}
On client side, you should send the list of files using the same key you gave in the endpoint (i.e., files in the case above) for each file.
files = [
('files', open('file1.zip', 'rb')),
('files', open('file2.txt', 'rb')),
('files', open('file3.rar', 'rb')),
]
You may also want to have a look at this and this answer.
In addition to the above, one shouldn't set the Content-Type in the headers
to multipart/form-data when using files, but rather let Python requests set the Content-Type, as in addition to multipart/form-data, Content-Type must include the boundary string used to separate each body part in the multipart payload). Please have a look at the answers here and here. Setting the Content-Type in the way you do is the reason for the error you encountered, i.e., {'detail': 'There was an error parsing the body'}. Thus, you should avoid setting the Content-Type in the headers.