google.appengine.datastore.datastore_rpc.ConfigOption

A descriptor for a Configuration option.

Inherits From: expected_type

google.appengine.datastore.datastore_rpc.ConfigOption(
    validator
)

This class is used to create a configuration option on a class that inherits from BaseConfiguration. A validator function decorated with this class will be converted to a read-only descriptor and BaseConfiguration will implement constructor and merging logic for that configuration option. A validator function takes a single non-None value to validate and either throws an exception or returns that value (or an equivalent value). A validator is called once at construction time, but only if a non-None value for the configuration option is specified the constructor's keyword arguments.

Methods

__call__

View source

__call__(
    *args
)

Gets the first non-None value for this option from the given args.

Args
*arg	Any number of configuration objects or None values.

Returns
The first value for this ConfigOption found in the given configuration

objects or None.

Raises
datastore_errors.BadArgumentError if a given in object is not a

configuration object.