example.py

def tobold(text):
    return md.bold(text)
  
# using tobold == md.bold
# because tobold(text) == md.bold(text)
# fun fact, you can alias the function
# tobold = md.bold

# unless you want to pre fill parameter
def header(text):
  return md.header(text, 1)

def toitalic(text):
    return md.italics(text)

def tostrike(text):
    return md.strikethrough(text)

def tomono(text):
    return md.bold(text)

def format_msg(tag,msg):
    switcher={
        'b': tobold(msg),
        'i': toitalic(msg),
        's': tostrike(msg),
    }
    # switcher will create a copy of the result of each
    # even if you're not using it
    return switcher.get(tag,msg)
  
# switcher can be outside since it only need to be initialised once
# also most importantly switcher is not intended to be mutated
switcher = {
    'b': md.bold,
    'i': md.italics,
    's': md.strikethrough,
}

def format_msg_minimal(tag, msg):
    func = switcher.get(tag)
    if not func:
      return msg # not formatted
    return func(msg)