Minimalist ROOT I/O in pure Python and Numpy.
uproot (or μproot, for “micro-Python ROOT”) is a demonstration of how little is needed to read data from a ROOT file. Only about a thousand lines of Python code can convert ROOT TTrees into Numpy arrays.
It is important to note that uproot is not maintained by the ROOT project team and it is not a fully featured ROOT replacement. Think of it as a file format library, analogous to h5py, parquet-python, or PyFITS. It just reads (and someday writes) files.