在我阅读了源代码之后，我发现我唯一要做的就是重写函数Completer。在

readline的函数Completer希望返回一个带有[state]的列表。在

prompt_toolkit.completion的函数Completer是一个生成函数，我们只需从单词列表中yield。在python3中，我们可以使用关键字yield from。在

代码应如下所示：from prompt_toolkit.completion import Completer, Completion

class MyCustomCompleter(Completer):

def get_completions(self, document, complete_event):

buffer = document.text

line = document.text.split()

COMMANDS = actions.keys()

# show all commands

if not line:

for i in [c for c in COMMANDS]:

yield Completion(i, start_position=-1 * len(document.text), display=i)

# account for last argument ending in a space

else:

if RE_SPACE.match(buffer):

line.append('')

# resolve command to the implementation function

cmd = line[0].strip()

if cmd in COMMANDS:

try:

impl = getattr(actions[cmd], 'complete')

except:

yield Completion(cmd, start_position=-1 * len(document.text))

else:

args = line[1:]

if args:

ret = impl(args)

if not ret:

pass

else:

for i in ret:

ret = cmd + ' ' + ' '.join(args[:-1]) + ' ' + i

ret = ' '.join(ret.split())

yield Completion(ret, start_position=-1 * (len(document.text)), display=i.split()[-1])

else:

yield Completion(cmd + ' ', start_position=-1 * len(document.text))

else:

results = [c for c in COMMANDS if c.startswith(cmd)]

for i in results:

yield Completion(i, start_position=-1 * len(document.text), display=i)

content = prompt(completer=MyCustomCompleter())