Python/Django: How to deserialize foo[]=1&foo[]=2&

Question

Is there a pre-built deserializer for query strings like:

foo[]=1&foo[]=2&foo[]=34&....&foo[]=5

Currently I am just working the string with replace and split to get a sequence with all the values, but I am curious if there isn't some utility/helper method in Python or Django to do this.

Obviously Django is able to do very similar things when processing requests, but I a) don't know if/how I can use it and b) if it is possible to receive a sequence from the foo[] notation.

Note: I am not able to change the source string, since it originates from a third party package.

UPDATE

Thanks for your replies. My values come from POST, so I did the following (not sure if there is a more direct way, like the answers used with request.GET.getlist()):

foo = QueryDict(request.POST.get('my_var_name')).getlist('foo[]')

@freakish: Probably jQuery; it's PHP's notation for an array being posted. — Martijn Pieters, May 29 '14 at 07:47
@MartijnPieters Oh, I've misunderstood. I thought he somehow wants to retrieve `foo` from that string. — freakish, May 29 '14 at 07:50
@freakish: see [Form input field names containing square brackets like field\[index\]](http://stackoverflow.com/q/4543500) — Martijn Pieters, May 29 '14 at 07:50
@MartijnPieters I see, thank you. Yet another reason not to use PHP. ;) — freakish, May 29 '14 at 07:52

score 2 · Answer 1 · answered May 29 '14 at 07:48

2

Firstly, there's absolutely no reason to send data with the [] prefix. That's a PHP or Rails idiom, and has no place in Django.

To get a list from a repeated parameter, though, you can just use getlist:

foos = request.GET.getlist('foo[]')

answered May 29 '14 at 07:48

Daniel Roseman

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@MartijnPieters I believe you can disable that in jQuery by setting `jQuery.ajaxSettings.traditional = true;`. – Daniel Roseman May 29 '14 at 07:55
Ah, I knew I'd missed a switch somewhere. Indeed, `traditional = true` will disable the dismal default setting. – Martijn Pieters May 29 '14 at 07:57
I'd really like to accept both of your answers. Came in exactly the same time. Super useful information with the ```traditional``` setting in jQuery. – sthzg May 29 '14 at 08:25

Martijn Pieters · Accepted Answer · 2018-09-28T11:32:06.120

2

Just retrieve all values with the getlist() method:

foo_list = request.GET.getlist('foo[]')

Include the brackets, they are just part of the name.

edited Sep 28 '18 at 11:32

answered May 29 '14 at 07:48

Martijn Pieters

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+1 for linking to the QueryDict docs. Useful read up and exactly what I was hoping to find. As noted, the part generating the bracketed string lives in a third party tool that I want to leave unchanged. – sthzg May 29 '14 at 08:32

Python/Django: How to deserialize foo[]=1&foo[]=2&

2 Answers2