prompt_toolkit.completionCompleter()的使用方法

The prompt_toolkit.completion.Completer() class in the prompt_toolkit library is used to implement autocompletion functionality in command-line applications. It provides a way to define custom autocomplete behavior, allowing users to receive suggestions as they type.

To use the prompt_toolkit.completion.Completer() class, you need to create a subclass and implement the get_completions() method. This method will be called every time a user requests autocompletion.

Here is an example of how to use the prompt_toolkit.completion.Completer() class:

from prompt_toolkit import PromptSession
from prompt_toolkit.completion import Completer

class MyCompleter(Completer):
    def __init__(self):
        # Initialize the completer with a list of available completions
        self.words = ['apple', 'banana', 'cherry', 'orange']
    
    def get_completions(self, document, complete_event):
        # Get the current word being completed
        line = document.current_line
        before_cursor = line[0:document.cursor_position]
        words = before_cursor.split()[-1]
        
        # Find completions that start with the current word
        completions = [word for word in self.words if word.startswith(words)]
        
        # Yield each completion
        for completion in completions:
            yield Completion(completion, start_position=-len(words))

# Create a PromptSession with custom Completer
completer = MyCompleter()
session = PromptSession(completer=completer)

# Run the prompt loop
while True:
    try:
        text = session.prompt('> ')
        print('You entered:', text)
    except KeyboardInterrupt:
        break

In the example above, we define a custom MyCompleter class that derives from Completer. In the get_completions() method, we split the current line and extract the last word being completed. We then generate a list of completions that start with the current word by iterating over the self.words list. Finally, we yield each completion using the Completion class provided by prompt_toolkit.

We create a PromptSession object with our custom completer and start the prompt loop. The user can now type a partial word and press the Tab key to see the available completions. Once the user selects a completion by pressing Enter or Tab, the selected completion will be inserted into the prompt text.

This is just a simple example of how to use prompt_toolkit.completion.Completer(). You can customize the behavior by implementing more complex logic in the get_completions() method. Additionally, prompt_toolkit provides other classes like WordCompleter and PathCompleter that you can use out-of-the-box for common completion use cases.