Phonopy is an open source package for phonon calculations at harmonic and quasi-harmonic levels. The following features of phonopy are highlighted: * Phonon band structure, phonon DOS and partial-DOS * Phonon thermal properties: Free energy, heat capacity (Cv), and entropy * Phonon group velocity * Thermal ellipsoids / Mean square displacements * Irreducible representations of normal modes * Dynamic structure factor for INS and IXS * Non-analytical-term correction: LO-TO splitting (Born effective charges and dielectric constant are required.) * Mode Gruneisen parameters * Quasi-harmonic approximation: Thermal expansion, heat capacity at constant pressure (Cp), * Interfaces to calculators: VASP, VASP DFPT, ABINIT, Quantu ESPRESSO, SIESTA, Elk, FHI-aims, WIEN2k, CRYSTAL * Python APIs WWW: https://atztogo.github.io/phonopy/