#NEWLINE# def length_3d( self ) : #NEWLINE# #INDENT# '\n        Computes 3-dimensional length of the GPX file (latitude, longitude, and\n        elevation). This is the sum of 3D length of all segments in all tracks.\n\n        Returns\n        ----------\n        length : float\n            Length returned in meters\n        ' #NEWLINE# result = 0 #NEWLINE# for track in self . tracks : #NEWLINE# #INDENT# length = track . length_3d ( ) #NEWLINE# if ( length or ( length == 0 ) ) : #NEWLINE# #INDENT# result += length #NEWLINE# #UNINDENT# #UNINDENT# return track