Google AppEngine tells me that my int is not an int

The relevant part of the code:

pk = int(pk)                              
logging.info('pk: %r :: %s', pk, type(pk))
instance = models.Model.get_by_id(int(pk))       

The output from the log message above

pk: 757347 :: <type 'int'>

The stacktrace:

Traceback (most recent call last):
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/__init__.py", line 634, in __call__
    handler.get(*groups)
  File "/base/data/home/apps/<myapp>/<version>/scrape.py", line 61, in get
    instance = models.Model.get_by_id(int(pk))
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", line 1212, in get_by_id
    return get(keys[0], config=config)
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", li开发者_StackOverflow中文版ne 1434, in get
    model = cls1.from_entity(entity)
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", line 1350, in from_entity
    instance = cls(None, _from_entity=True, **entity_values)
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", line 890, in __init__
    prop.__set__(self, value)
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", line 593, in __set__
    value = self.validate(value)
  File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/db/__init__.py", line 2967, in validate
    % (self.name, type(value).__name__))
BadValueError: Property pk must be an int or long, not a unicode

Anyone has an idea if I'm doing something wrong here?

Note: removing the int from the last line of the code makes no difference (that was the first version).

Also, the code works without a problem on dev_appserver.py.

Does your model have a property 'pk', which is now an IntegerProperty(), but was previously a StringProperty(), and the entity with id 757347 was saved with the old version of the model?

Create a custom validator for your pk IntegerProperty.

I think @saxon-druce has the right idea about what is failing.

You are receiving an entity from datastore and the from_entity function is apply the data from the entity to an initializer for your db.Model.

validate call is from google/appengine/ext/db/__init__.py

From SDK

class IntegerProperty(Property):
  """An integer property."""

  def validate(self, value):
    """Validate integer property.

    Returns:
      A valid value.

    Raises:
      BadValueError if value is not an integer or long instance.
    """
    value = super(IntegerProperty, self).validate(value)
    if value is None:
      return value





    if not isinstance(value, (int, long)) or isinstance(value, bool):
      raise BadValueError('Property %s must be an int or long, not a %s'
                          % (self.name, type(value).__name__))
    if value < -0x8000000000000000 or value > 0x7fffffffffffffff:
      raise BadValueError('Property %s must fit in 64 bits' % self.name)
    return value

  data_type = int

Create your own trivial validator that attempts to parse an string as an int. Eventually you would probably want to apply a mapper across all of these entities to bring them all up to the current schema.

The validator is called inside value = super(IntegerProperty, self).validate(value) so the value should be ready to use as an int at the appropriate time.

Example Validator

def str_int_validator(value):
    if isinstance(value, basestring):
        if value.isdigit():
            return int(value)
        else:
            raise db.BadValueError("Property expected str or int got %r" % value)
    else:
        return value

class Foo(db.Model):

    pk = db.IntegerProperty(validator=str_int_validator)

This code hasn't been tested.

I had the same error message after deleting all elements in one entity/table and then trying to upload new values via csv/bulkloader.

The solution was to add the following line

import_transform: transform.none_if_empty(int)

to the property definition in the yaml file for the bulk loader.