DeserializationError: maximum recursion depth exceeded while calling a Python object

Question

I'm trying to load fixtures into my Django (1.4) app via converting CSVs with the data into json files, and then feeding those into Django with loaddata. But I keep getting a max recursion depth error. I've looked around, and it seems to be connected to non-ASCII characters in the json files. However, I'm pretty sure I'm not doing that? Here's my code:

    def csv_to_json(self,csv,dest,model,keys,sub):
    #keys is a dict formatted x:f where x = index of value v;
    #don't include pk
    with open(csv) as f:
        l = f.readlines()
    right = len(l[0].split(","))
    out = []
    for x in xrange(1,len(l)):
        if sub:
            line = re.sub(", "," ",l[x])
        line = re.sub(r'(,[\'\"*.]+|[\'\"*.]+,)','',l[x])
        line = unicodedata.normalize('NFKD',unicode(line,'utf-8','ignore')).encode('ASCII','ignore')
        line.encode('ASCII')
        splt = line.split(",")
        print len(splt) 
        if len(splt) == right:
            for y in xrange(len(splt)):
                if re.match(r'\d{4}-\d{2}-\d{2}',str(splt[y])):
                    splt[y] = int(splt[y][:4])
                try:
                    if splt[y].isupper():
                        splt[y] = splt[y].title()
                    splt[y] = splt[y].rstrip()
                except AttributeError:
                    continue
                try:    
                    splt[y] = int(splt[y])
                except ValueError:
                    try:
                        splt[y] = float(splt[y])
                    except ValueError:
                        continue

            d = {}
            d["model"] = "dishes.%s"%(model)
            d["pk"] = splt[0]
            d["fields"] = {}
            for k,v in keys.items():
                print v,k
                try:
                    d["fields"][v] = splt[k]
                except IndexError:
                    continue
            out.append(d)
    with open(dest,"w") as f:
        json_out = simplejson.dump(out,f,separators=(",",":"))

As you can see, I AM briefly turning the contents of the CSVs into UTF-8 for the purposes of using unicodedata to scrub them of diacritics (which I had to do because I was getting "invalid continuation character" messages when I tried to load them with loaddata), but then I'm converting everything back into ASCII. Or am I? If I am, then what's causing the recursion problem?

ETA: Here's the error message in full:

Problem installing fixture
'/Users/samuelraker/django/menus/menus/dishes/fixtures/Classification.json':                
Traceback (most recent call last):
File "/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/commands/loaddata.py", line 190, in handle
for obj in objects:
File "/usr/local/Cellar/python/2.7.3/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/serializers/json.py", line 47, in Deserializer
raise DeserializationError(e)
DeserializationError: maximum recursion depth exceeded while calling a Python object

Re-edited to further add: Here's a snippet of one of the JSON files I'm trying to load.

[
{
    "pk":1,
    "model":"dishes.dish",
    "fields":{
        "name":"Consomme printaniere royal"
    }
},
{
    "pk":2,
    "model":"dishes.dish",
    "fields":{
        "name":"Chicken gumbo"
    }
},
{
    "pk":3,
    "model":"dishes.dish",
    "fields":{
        "name":"Tomato aux croutons"
    }
},
{
    "pk":4,
    "model":"dishes.dish",
    "fields":{
        "name":"Onion au gratin"
    }
},
{
    "pk":5,
    "model":"dishes.dish",
    "fields":{
        "name":"St. Emilion"
    }
},
{
    "pk":7,
    "model":"dishes.dish",
    "fields":{
        "name":"Radishes"
    }
},
{
    "pk":8,
    "model":"dishes.dish",
    "fields":{
        "name":"Chicken soup with rice"
    }
},
{
    "pk":9,
    "model":"dishes.dish",
    "fields":{
        "name":"Clam broth (cup)"
    }
},
{
    "pk":11,
    "model":"dishes.dish",
    "fields":{
        "name":"Clear green turtle"
    }
},
{
    "pk":13,
    "model":"dishes.dish",
    "fields":{
        "name":"Anchovies"
    }
},
{
    "pk":14,
    "model":"dishes.dish",
    "fields":{
        "name":"Fresh lobsters in every style"
    }
},
{
    "pk":15,
    "model":"dishes.dish",
    "fields":{
        "name":"Celery"
    }
},
{
    "pk":16,
    "model":"dishes.dish",
    "fields":{
        "name":"Pim-olas"
    }
},
{
    "pk":17,
    "model":"dishes.dish",
    "fields":{
        "name":"Caviar"
    }
},
{
    "pk":18,
    "model":"dishes.dish",
    "fields":{
        "name":"Sardines"
    }
},
{
    "pk":19,
    "model":"dishes.dish",
    "fields":{
        "name":"India chutney"
    }
},
{
    "pk":20,
    "model":"dishes.dish",
    "fields":{
        "name":"Pickles"
    }
},
{
    "pk":21,
    "model":"dishes.dish",
    "fields":{
        "name":"English walnuts"
    }
},
{
    "pk":22,
    "model":"dishes.dish",
    "fields":{
        "name":"Pate de foies-gras"
    }
},
{
    "pk":23,
    "model":"dishes.dish",
    "fields":{
        "name":"Pomard"
    }
},
{
    "pk":26,
    "model":"dishes.dish",
    "fields":{
        "name":"Clams"
    }
},
{
    "pk":27,
    "model":"dishes.dish",
    "fields":{
        "name":"Oysters"
    }
},
{
    "pk":28,
    "model":"dishes.dish",
    "fields":{
        "name":"Claremont planked shad"
    }
},
...

EDIT 3: Happy Holidays! I just pasted a small snippet of one of the JSON files into a separate file, ran it through JSONLint just to make sure, and then passed it to loaddata...and I got the same darn error message. Could it be a problem with my models?

EDIT 4: So I tried encoding my data as YAML instead of JSON, and it didn't work. I'm really stumped here guys. Someone PLEASE help!

EDIT 5: I even tried changing my db backend to django-mysql-pymysql (http://pypi.python.org/pypi/django-mysql-pymysql/0.1), but that didn't work either. Anyone? Please?

Answer 1

Turns out, the problem was that I had a field in my models called 'pk' with 'primary_key=True'. It'd be nice if there was a list of 'reserved words' for Django, since my mistake seems fairly easy to make, and, without using the shell for debugging, is tricky to catch. I also had problems with manually-defined fields ending in "_id," which isn't documented either, AFAIK.