Appengine create and export yaml file

Question

I´m having trouble in creating a file and export to .yaml. I´m using Google App Engine with Python 2.5. Don´t understand the Yaml doc´s, it makes me confused.

What i want is to create a file and save it. It´s necessary to get entities from Models.

class SaveYAML(webapp.RequestHandler):
    def post(self):
        user = db.Query(models.User)
        user = user.filter('user =', users.get_current_user())
        users = user.fetch(limit = 1)

        for user in users:
            print(user.name, user.adress, user.phone, user.city)

        self.response.headers['Content-Type'] = 'application/yaml'
        self.response.headers['Content-Disposition'] = 'filename = myYaml.yaml' 

With this snippet i can view in a browser, when i click in a button the information retrieved from models. Maybe it´s because of print method, but it doesn´t create a file But when i upload my app to Google App Engine it doesn´t show the same info. It shows only 'Status 200 Ok'.

Can someone point me in the right direction? Do i have to import pyyaml library?

I changed some code to:

print(yaml.dump(user, sys.stdout))

and the result was this in a browser:

- !!binary |
  /9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
  HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
  MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAAnACgDASIA
  AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA
  AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3
  ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm
  p6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEA
  AwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSEx
  BhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElK
  U1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3
  uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD2WxvX
  h8zzNxhEjgk87fmPI9R6+lbKsGUMpBBGQR3rAhKxRTyOyqglck9Mc1nX/iVdGb7JZr9qnlBMcCc7
  T3Psvqeg7elAG7rmv6f4esGu7+ZUXoq5+Zz6Cuc8I+ItS8X6pLqK/wCiaXbKYhbjkyuRnJOOw7Cs
  jXvC8epW0Ta5IdR1O7dTFDG5Eaeirj1xy3oG6dK7rQdGtvDuiQ2FuoCRLl2A+8x5J/OtFKKhtqZu
  MnPfQoajeXDeLtMtICfLG55cNj5Qp6/iVoqLQAb/AMQalqLDKoRBGf1NFceGqOpT9o+t/u6fgdNZ
  csuTt/T/ABMGTVb/AFu4NroW37H5rG5upEOB83AUHr9O/r2roI9DtfDsUt1GHmaTBmmc5kLdBz6d
  sdB246XrcIlpKgXaPNOOBz8wqtqkFxreoRWSKRp0ZJuJM43H+6PXPTPufw6DIytCk/0ttauQv2d8
  rbr3Ck8yKPQ9AP7oB7muk1m+S00We5VgVKfKQeDVe80yO3+eFAIO6gf6v6f7P8vpXP63lfsmnbnM
  c8ykoozhepIrlxk3Gi1Hd6L1ehrQinUV9lr92p0PhezNnoMAcfvJcyv9W5orWhKGFDEQU2jaR0xR
  XRCKhFRjsjOUnJuT6mALmOIyxujHMjE4478d6kXUUXIHnAZ/vH8e9FFUIY2roq8+dn03HH86wYby
  3bxFLduji3twYolxk5IyT196KKTipWv0GpNXsbNv4gtYZ/kEgjY/MpXoe5HP/wCv+ZRRTEf/2Q==
_name: !!python/unicode 'Ana Ferreira'
_parent: null
_parent_key: null
_adress: !!python/unicode 'Porto'
_phone: !!python/unicode '1234569789'
_user: *id002
None
Status: 200 OK
Cache-Control: no-cache
Content-Type: text/yaml
Content-Disposition: filename = myYaml.yaml
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Content-Length: 0

Changed the code, but the data is only presented by browser.

Answer 1

Do not use print, use self.response.out.write(...).

Yes, you will want to import yaml to output yaml, it will make it easier.

Try this:

import yaml

users = model.Users.all().fetch(10)
users = [{'user': {'name': user.name,
                   'address': user.address,
                   'phone': user.phone,
                   'city': user.city}}
          for user in users]

self.response.out.write(yaml.dump(users, default_flow_style=False))

You can check out the yaml docs for additional information on formatting the output.