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Functions

DerivedProperty

Derived datastore property.

Derived properties are not set directly, but are instead generated by a function when required. They are useful to provide fields in the datastore that can be used for filtering or sorting in ways that are not otherwise possible with unmodified data - for example, filtering by the length of a BlobProperty, or case insensitive matching by querying the lower cased version of a string.

DerivedProperty can be declared as a regular property, passing a function as the first argument, or it can be used as a decorator for the function that does the calculation, either with or without arguments.

Classes

LengthProperty

Convenience class for recording the length of another field.

LowerCaseProperty

A convenience class for generating lower-cased fields for filtering.