code: def read_piezo_tensor(self):
          
          header_pattern = r"PIEZOELECTRIC TENSOR  for field in x, y, " \
                           r"z\s+\(C/m\^2\)\s+([X-Z][X-Z]\s+)+\-+"
          row_pattern = r"[x-z]\s+" + r"\s+".join([r"(\-*[\.\d]+)"] * 6)
          footer_pattern = r"BORN EFFECTIVE"
          pt_table = self.read_table_pattern(header_pattern, row_pattern,
                                             footer_pattern, postprocess=float)
          self.data["piezo_tensor"] = pt_table
docs: Parse the piezo tensor data