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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def read_array(path, mmap_mode=None):
 """Read a .npy array."""

    file_ext = op.splitext(path)[1]
    if file_ext == '.npy':
        return np.load(path, mmap_mode=mmap_mode)
    raise NotImplementedError("The file extension `{}` ".format(file_ext) +
                              "is not currently supported.")