Question

My GAE app runs fine from my computer, but when I upload it, I start getting an AttributeError, specifically:

AttributeError: 'dict' object has no attribute 'item'

I am using the pylast interface (an API for last.fm–link). Specifically, I am accessing a list of variables of this type:

SimilarItem = _namedtuple("SimilarItem", ["item", "match"])

I have a variable of this type, call it sim, and I am trying to access sim.item when I get the attribute error.

I should note that I am using Python 2.6 on my computer, and I understand that GAE runs on Python 2.5. Would that make a difference here? I thought they were backwards-compatible.

Lastly, I think it could be a possible problem with the modules that pylast imports–maybe they don’t work with GAE or something? I did some research but I didn’t get any results. Here are the imports:

import hashlib
import httplib
import urllib
import threading
from xml.dom import minidom
import xml.dom
import time
import shelve
import tempfile
import sys
import htmlentitydefs

I would appreciate any help with this frustrating issue. Thanks in advance.

Answer 1

Python 2.5 doesn’t have namedtuple. It was added in 2.6.

Edit: It looks like the _namedtuple function is provided by pylast and will use a real namedtuple in Python 2.6+ but will fall back to a plain old dict in Python 2.5 or older. That means that you’ll have to use sim['item'] or sim.get('item') when running in production.

Here’s the source for that function:

def _namedtuple(name, children):
    """
        collections.namedtuple is available in (python >= 2.6)
    """

    v = sys.version_info
    if v[1] >= 6 and v[0] < 3:
        return collections.namedtuple(name, children)
    else:
        def fancydict(*args):
            d = {}
            i = 0
            for child in children:
                d[child.strip()] = args[i]
                i += 1
            return d

        return fancydict