code: def parse_dtype(features, check=True):
      
      dtype = features[0].dtype
      if check:
          types = [x.dtype for x in features]
          if not all([t == dtype for t in types]):
              raise IOError('features must be homogeneous')
      return dtype
docs: Return the features scalar type, raise if error
  
      Raise IOError if all features have not the same data type.
      Return dtype, the features scalar type.