a simple demo of pipeline pattern for python

pipeline_pattern.py

def processor1(obj):
  """Require: text; yield firstchar"""
  obj['firstchar'] = obj.text[:1]
  return obj

def processor2(obj):
  """Require: firstchar, text2; yield concat"""
  obj['concat'] = obj.firstchar + obj.text2
  return obj

procs = [
  processor1, 
  processor2
]

obj = {
  text: "Kr",
  text2: " 233..."
}

for proc in procs:
  proc(obj)
  
print obj