DCA Access Standard Security Program (DASSP) On July 19, 2005, the Transportation Security Administration (TSA) released an interim final rule that allows certain general aviation aircraft to apply for access to Ronald Reagan Washington National Airport (DCA) under the DCA Access Standard Security Program (DASSP).
The basic operations that can be performed on a binary search tree data structure, are the following 1  â. Insert â Inserts an element in a tree/create a tree. 2  Search â Searches an element in a tree. 3  Preorder Traversal â Traverses a tree in a pre-order manner. 4  Inorder Traversal â Traverses a tree in an in-order manner.
Selecting columns of a DataFrame. Selecting the data in specific columns of a DataFrame is performed by using the [] operator. This can be passed either as a single object, or a list of objects. These objects are then used to lookup columns either by zero-based location, or by matching the objects to the values in the columns index.