CLI在足球数据发生器中的应用

Question

我试图构建一个CLI，直到用户决定退出为止。CLI的功能是能够在程序运行时通过在终端中键入命令来探索json文件。

现在，命令是根据if/else语句进行检查的，但我想添加一下，以便以argparse模块的方式检查命令，但不知道在程序运行时是如何完成的。因为我无法理解这一点，所以类方法被映射到特定的命令，并在指定命令时执行，而不必依赖于if/else逻辑。

最大的问题不是像-v那样的单个命令，因为它们很容易映射到带有dict的函数。但是，在-v LEAGUE命令中，LEAGUE或-d LEAGUE SEASON TYPE在不创建大型字典的情况下很难映射，因为参数可能会有所不同。任何关于如何改进的建议都是非常感谢的！

import os
import sys


class CLIStats:

    def __init__(self):
        """Displays the welcome screen and loads the season-params.json
        which contains the avalible leagues and their seasons that
        can be downloaded. Pickled with pre-proccessed IDs is also loaded.
        """
        self.header = self.header()
        self.description = self.description()
        self.commands = self.commands()
        self.leagues = {'EN_PR': ['2019/2020', '2018/2019', '2017/2018', '2016/2017'],
                        'EU_CL': ['2019/2020', '2018/2019', '2017/2018', '2016/2017'],
                        'ES_PL': ['2019/2020', '2018/2019', '2017/2018', '2016/2017']}

    @staticmethod
    def header():
        """Display's welcome message"""
        os.system('clear')
        print('\t','*'*60)
        print("\t\t***  Welcome - Football Stats generator  ***")
        print('\t','*'*60)

    @staticmethod
    def description():
        """Display's short description"""
        print('Interface to download: \t playerstats \t fixturestats \t team standing \n')
        print('Type "exit" to terminate shell')

    @staticmethod
    def commands():
        """Display's avalible commands and how to use them"""
        commands = {'View Leagues': '-v',
                    'View League Seasons': '-v LEAGUE',
                    'Download stats': '-d LEAGUE SEASON TYPE',
                    'Help' : '-h',}
        for key, value in commands.items():
            print("{: <25} {}".format(key, value))
        print('\n')

    def view_leagues(self):
        """Prints out leagues in self.leagues"""
        for league in self.leagues.keys():
            print("{: <10}".format(league), end="")
        print('\n')

    def view_seasons(self, league):
        """Prints seasons for a league in self.leagues"""
        if league in self.leagues:
            seasons = self.leagues[league]
            print(league,'seasons:')
            for season in seasons:
                print("{: <20}".format(season), end="")
            print('\n')
        else:
            print(league, 'is not avalible')
            print('\n')

    def view_league_args(self):
        """Creates a list with set of args that can be passed
        by user to execute view_league()"""
        args = []
        for league in self.leagues.keys():
            args.append('-v' + ' ' +  league)
        return args  

def main():
    """Runs the interface"""
    interface = CLIStats()
    cmd = {'-v': interface.view_leagues,
           'exit': sys.exit,
           'View Stats Type': '-s',
           '-h' : 'interface.help', }
    while True:
        usr_command = input('CLIStats$ ')
        if usr_command in cmd.keys():
            cmd.get(usr_command)()

        elif usr_command in interface.view_league_args():
            league = usr_command.split(' ')[-1]
            interface.view_seasons(league)

        elif len(usr_command.split(' ')) == 4:
            league = usr_command.split(' ')[1]
            season = usr_command.split(' ')[2]
            stat_type = usr_command.split(' ')[3]
            interface.download_stats(league, season, stat_type)

        else:
            if usr_command.split(' ')[0] not in cmd.keys():
                print('Command not valid')
            else:
                print('Could not find the specified params')

if __name__ == '__main__':
    main()

Answer 1

cmd.Cmd

虽然argparse()可能被滥用来提供一些所需的功能，但它不是正确的工具。例如，它设计为在检测到错误时退出，例如无法识别的命令或缺少参数。

标准库中的cmd是一个更好的工具。编写命令解释器就像编写cmd.Cmd的子类和为每个命令定义"do_command“方法一样简单，例如do_view()、do_download()等。下面是一个基于代码的示例，但是"do_command()”方法只是打印一些东西。

import cmd 

class StatShell(cmd.Cmd):
    intro = '\n'.join([
        "\t" + "*"*60,
        "\t\t***  Welcome - Football Stats generator  ***",
        "\t" + "*"*60,
        "",
        "\tType help or ? to list commands,",
        "\t\tor help command to get help about a command."
    ])
    prompt = "CLIStats: "


    def do_download(self, arg):
        """Download statistics: download LEAGUE SEASON TYPE"""
        arg = arg.split()
        if len(arg) == 3:
            league, season, type = arg
            print(f"downloading {league} {season} {type}")
        else:
            self.error("bad 'download' command.")


    def do_exit(self, arg):
        """Exit the interpreter."""
        print("exiting ...")
        return True


    def do_view(self, arg):
        """view leagues or seasons: view [LEAGUE] """
        if arg:
            league = arg[0]
            print(league,'seasons: ...')

        else:
            print('leagues ...')


def main():
    StatShell().cmdloop()

Answer 2

联盟代表

这是：

    self.leagues = {'EN_PR': ['2019/2020', '2018/2019', '2017/2018', '2016/2017'],
                    'EU_CL': ['2019/2020', '2018/2019', '2017/2018', '2016/2017'],
                    'ES_PL': ['2019/2020', '2018/2019', '2017/2018', '2016/2017']}

看上去太过分了。充其量，您需要存储：

• 作为int的最小和最大年数
• 联赛名称集：{'EN_PR', 'EU_CL', 'ES_PL'}

其他的一切都可以衍生出来。

语法

Display's avalible commands and how to use them

至

Displays available commands and how to use them

和

is not avalible

至

is not available

发生器

    args = []
    for league in self.leagues.keys():
        args.append('-v' + ' ' +  league)
    return args  

可以是

return ' '.join(f'-v {league}' for league in self.league_names)

假设league_names持有前面描述的集合。