code: def signstr(x, noplus=False):
      if x in [-1, 0, 1]:
          if not noplus:
              return "+" if np.sign(x) >= 0 else "-"
          else:
              return "" if np.sign(x) >= 0 else "-"
      else:
          return str(x)
  
imports: from numpy.testing import assert_equal
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: signstr(x, noplus) and returns: str, unknown, unknown