code: def micro_calc(item1, item2):
      """
      Calculate TPR, TNR, PPV, NPV, FNR, FPR, or F1 micro.
  
      :param item1: item1 in micro averaging
      :type item1:dict
      :param item2: item2 in micro averaging
      :type item2: dict
      :return: PPV, NPV, TPR, TNR, FNR, FPR, or F1 micro as float
      """
      try:
          item1_sum = sum(item1.values())
          item2_sum = sum(item2.values())
          return item1_sum / (item1_sum + item2_sum)
      except Exception:
          return "None"
  
imports: from __future__ import division
  import math
  import operator
  from functools import reduce
  from .pycm_interpret import *
  from .pycm_ci import kappa_SE_calc, CI_calc, SE_calc
  from .pycm_util import complement
label_desc: Use image node_id 36 for calling a global function with example usage: micro_calc(item1, item2) and returns: unknown, str