code: def num2binary(l, bits=32):
      items = []
      binary = ""
      for i in range(bits):
          if l & 0x1:
              binary = "1" + binary
          else:
              binary = "0" + binary
          l = l >> 1
          if not ((i + 1) % 8):
              items.append(binary)
              binary = ""
      if binary:
          items.append(binary)
      items.reverse()
      assert l in (0, -1), "number doesn't fit in number of bits"
      return " ".join(items)
  
imports: import ast
  import string
label_desc: Use image node_id 4 for calling a global function with example usage: num2binary(l, bits) and returns: str