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. Specif-
ically, simulated 1 GeV/c charged pions and protons are
correctly reconstructed and identified with efficiencies of
86.1±0.6% and 84.1±0.6%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of
those predicted by the simulation.