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Form sending error, Flask- Stack Overflow

Python PingBook 1 months ago (10-23) 19 0


There is form with two . But when i’m sending it, second submit causes error.



if request.method == ‘POST’:
if request.form[‘add’]:
return redirect(url_for(‘index’))
elif request.form[‘remove’]:
return redirect(url_for(‘index’))

First submit(add) works well, but second(remove)…:

Bad Request The browser(or proxy) sent a request that this server could not understand.

How can i fix this error?


It was pretty simple:
request.form returns ImmutableMultiDict:

if ‘Like’ in request.form.values():

elif ‘Dislike’ in request.form.values():


As @Blubber points out, the issue is that Flask raises an HTTP error when it fails to find a key in the args and form dictionaries. What Flask assumes by default is that if you are asking for a particular key and it’s not there then something got left out of the request and the entire request is invalid.

There are two other good ways to deal with your situation:

Use request.form’s .get method:

if request.form.get(‘add’, None) == “Like”:
# Like happened
elif request.form.get(‘remove’, None) == “Dislike”:
# Dislike happened

Use the same name attribute for both submit elements:

# and in your code
if request.form[“action”] == “Like”:
# etc.

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