code: def _split(f, s, a_p="", a_s="", b_p="", b_s="", reverse=False):
      """Split string on a symbol and return two string, first possible empty"""
      splitted = f.split(s)
      if len(splitted) == 1:
          a, b = "", splitted[0]
          if reverse:
              b, a = a, b
      else:
          a, b = splitted
  
      if a:
          a = "%s%s%s" % (a_p, a, a_s)
      if b:
          b = "%s%s%s" % (b_p, b, b_s)
  
      return a, b
  
file_path: mlens/mlens/metrics/utils.py
imports: from __future__ import division
  import warnings
  import numpy
  from ..utils.exceptions import MetricWarning
label_desc: Use image node_id 3 for calling a global function with example usage: _split(f, s, a_p, a_s, b_p, b_s, reverse) and returns: a,  b