Why am I seeing “TypeError: string indices must be integers”?

I’m playing with both learning Python and am trying to get GitHub issues into a readable form. Using the advice on How can I convert JSON to CSV?, I came up with this:

import json
import csv

f = open('issues.json')
data = json.load(f)
f.close()

f = open("issues.csv", "wb+")
csv_file = csv.writer(f)

csv_file.writerow(["gravatar_id", "position", "number", "votes", "created_at", "comments", "body", "title", "updated_at", "html_url", "user", "labels", "state"])

for item in data:
    csv_file.writerow([item["gravatar_id"], item["position"], item["number"], item["votes"], item["created_at"], item["comments"], item["body"], item["title"], item["updated_at"], item["html_url"], item["user"], item["labels"], item["state"]])

Where “issues.json” is the JSON file containing my GitHub issues. When I try to run that, I get

File "foo.py", line 14, in <module>
csv_file.writerow([item["gravatar_id"], item["position"], item["number"], item["votes"], item["created_at"], item["comments"], item["body"], item["title"], item["updated_at"], item["html_url"], item["user"], item["labels"], item["state"]])

TypeError: string indices must be integers

What am I missing here? Which are the “string indices”? I’m sure that once I get this working I’ll have more issues, but for now, I’d just love for this to work!

When I tweak the for statement to simply

for item in data:
    print item

what I get is … “issues” — so I’m doing something more basic wrong. Here’s a bit of my JSON content:

{"issues": [{"gravatar_id": "44230311a3dcd684b6c5f81bf2ec9f60", "position": 2.0, "number": 263, "votes": 0, "created_at": "2010/09/17 16:06:50 -0700", "comments": 11, "body": "Add missing paging (Older>>) links...

when I print data, it looks like it is getting munged really oddly:

{u'issues': [{u'body': u'Add missing paging (Older>>) lin...