  The Pandora Software Development Kit and algorithm libraries provide
pattern-recognition logic essential to the reconstruction of particle
interactions in liquid argon time projection chamber detectors. Pandora is the
primary event reconstruction software used at ProtoDUNE-SP, a prototype for the
Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at
CERN, is exposed to a charged-particle test beam. This paper gives an overview
of the Pandora reconstruction algorithms and how they have been tailored for
use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam
background particles, the simulated reconstruction and identification
efficiency for triggered test-beam particles is above 80% for the majority of
particle type and beam momentum combinations. Specifically, simulated 1 GeV/$c$
charged pions and protons are correctly reconstructed and identified with
efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies
measured for test-beam data are shown to be within 5% of those predicted by the
simulation.
