EMD (Electron Microscopy Dataset) 1.0 is an HDF5 based file format which is designed to carry arbitrary data and metadata. emdfile is a Python package defining write and read functions and a set of classes which together interface between EMD 1.0 files and Python runtime objects. The classes are designed to quickly build, save to, and read from filetree-like representations of data and metadata, and is built on HDF5+h5py.