Google app engine python 2.7 tutorial won't run

Question

I'm following the tutorial at https://developers.google.com/appengine/docs/python/gettingstartedpython27/introduction

my app.yaml is:

application: myapp
version: 1
runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /
  script: helloworld.application

and helloworld.py is:

import webapp2


class MainPage(webapp2.RequestHandler):

    def get(self):
        self.response.headers['Content-Type'] = 'text/plain'
        self.response.write('Hi')


application = webapp2.WSGIApplication([
    ('/', MainPage),
], debug=True)

The log output is:

*** Running dev_appserver with the following flags:
    --skip_sdk_update_check=yes --port=10090 --admin_port=8001
Python command: /usr/bin/python2.7
Traceback (most recent call last):
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 182, in <module>
    _run_file(__file__, globals())
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/dev_appserver.py", line 178, in _run_file
    execfile(script_path, globals_)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 695, in <module>
    main()
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 688, in main
    dev_server.start(options)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 525, in start
    options.yaml_files)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/application_configuration.py", line 556, in __init__
    server_configuration = ServerConfiguration(yaml_path)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/application_configuration.py", line 82, in __init__
    self._yaml_path)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/tools/devappserver2/application_configuration.py", line 272, in _parse_configuration
    return appinfo_includes.ParseAndReturnIncludePaths(f)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/appinfo_includes.py", line 63, in ParseAndReturnIncludePaths
    appyaml = appinfo.LoadSingleAppInfo(appinfo_file)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/appinfo.py", line 1715, in LoadSingleAppInfo
    listener.Parse(app_info)
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/yaml_listener.py", line 226, in Parse
    self._HandleEvents(self._GenerateEventParameters(stream, loader_class))
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/yaml_listener.py", line 177, in _HandleEvents
    raise yaml_errors.EventError(e, event_object)
google.appengine.api.yaml_errors.EventError

I'm running on a macbook pro, using python 2.7 I'm using the app engine launcher. Any ideas?

Answer 1

I experienced the same problem too. It has something to do with the file encoding when you copy directly from the site. Avoid doing this and ensure that your file has proper yaml encoding. Here's an example to get you started for the app.yaml file

application: your-app-id
version: 1
runtime: python27
api_version: 1
threadsafe: true

handlers:
- url: /.*
  script: helloworld.application

Answer 2

In my case the problem was the indentation level of the "script" line.

It was like:

handlers:
 - url: /.*
 script: helloworld.php

but should be like this:

handlers:
 - url: /.*
   script: helloworld.php