In Django, the canonical way of processing forms is:
if request.method == 'POST':
form = SomeForm(request.POST)
if form.is_valid():
use the form data
I want to execute the same code whether there was no POST or the form was invalid - it's a few lines of code, so I'm wondering if there is a nicer way of doing this than having two duplicate else blocks (one for the inner if and one for the outer)?
Use a separate function:
if request.method != 'POST':
return do_something_function_for_invalid(request)
form = SomeForm(request.POST)
if not form.is_valid():
return do_something_function_for_invalid(request)
# do something
and then define do_something_function_for_invalid() as:
def do_something_function_for_invalid(request):
# do something
return response
Alternatively, use exception handling:
try:
if request.method != 'POST':
raise ValueError('invalid form')
form = SomeForm(request.POST)
if not form.is_valid():
raise ValueError('not a POST request')
# do something
except ValueError as ve:
# handle ve exception, ve.args[0] is the error message
do_something_function locally and don't worry about passing arguments.
else statements.
A very concise way that does not require a separate function, and doesn't repeat conditions:
form = SomeForm(request.POST) if request.method == 'POST' else None
if form and form.is_valid():
# do your valid-submission stuff
else:
# do your invalid-submission stuff
As simple as
if (request.method != 'POST') or (not SomeForm(request.POST).is_valid()):
do something
SomeForm object is probably crucial.