带有多级解析器/子解析器的Argparse可选参数 [英] Argparse optional arguments with multilevel parser/subparser

问题描述

我有一组解析器和子解析器，用于构建生产或开发系统.如果用户选择生产，则可以添加选项，一切都很好.
如果他开发照片，则可以输入架构，然后输入构建选项.这就是它变粘的地方.我希望他能够选择构建选项"comms"，"server"或"all"，但是如果他选择服务器，则他还有更多选择.

I have a set of parsers and subparsers to build a production or development system. If the user picks production, he can add options and all is well.
If he pics development, he can enter an architecture and then enter build options. This is where it gets sticky. I want him to be able to select build option 'comms' 'server' or 'all', but if he picks server, he has more choices.

我的实现如下.我尝试了解析器和子贴子的组合(看来参数只能添加到解析器中，不能添加到子解析器中，对吗?)

My implementation is below. I tried combinations of parsers and subpasers (it seems that arguments can only be added to parsers, not subparsers, is that correct?)

它分崩离析有两个原因:
1)我只能选择拱门或建筑，而我必须同时选择两者
2)如果我选择构建，那么即使我选择其他两个之一，也总是要求我选择服务器".

It falls apart for 2 reasons:
1) I can only select arch or build and I need to select both
2) If I select build it always requires that I pick 'server', even if I pick one of the other two.

所以我想要这样的东西./buildServer.py Dev arch -arm build -comms或者./buildServer.py Dev arch -arm build -server -tcp

So I would like something like this ./buildServer.py Dev arch -arm build -comms or ./buildServer.py Dev arch -arm build -server -tcp

我将非常感谢和帮助/指导-TIA

I'd appreciate and help/guidance I can get - TIA

代码:

def verify():

def verify():

main_parser = argparse.ArgumentParser()     
main_subparsers = main_parser.add_subparsers(title="main", dest="main_command")          

# parser production choices                                                                                                     
prod_parser = main_subparsers.add_parser("prod", help="Prod")     
prod_parser.add_argument("-c",  "--change",   action='store_true', dest="change_sig", default=False, help="Change signature information (default = %(default)s)")
prod_parser.add_argument("-sd", "--sign-deb",  action='store_true', dest="sign_deb",   default=False, help="Add signature to the .deb file (default = %(default)s)")
prod_parser.add_argument ("-i",  "--install",  action='store_true', dest="build_deb" , default=False, help="Build .deb file from existing structure (default = %(default)s)")

# parser for development                                                                                                   
dev_parser = main_subparsers.add_parser("Dev", help="Dev")                                                                                                              
dev_subparser = dev_parser.add_subparsers(title="devsubparser")     

# optional development architecture choices
action_arch_parser = dev_subparser.add_parser("arch", help="architecture")
dev_arch_group = action_arch_parser.add_mutually_exclusive_group()
dev_arch_group.add_argument("-x86",  action='store_const', dest="architecture", const='x', default='x',help="Build dev code on X86")
dev_arch_group.add_argument("-arm",  action='store_const', dest="architecture",     const='a', help="Build dev code on arm")

# development build choices - 2 arguments (coms / all) and a third (server) that has its own options.
dev_build_parser = dev_subparser.add_parser("build", help="build")
dev_build_parser.add_argument("-comms", action='store_true',  help="Build comms program")
dev_build_parser.add_argument("-all", action='store_true',  help="Build all programs")
server_parser = dev_build_parser.add_subparsers(title="server", help="server subparser")
server_parser_p = server_parser.add_parser("server", help="server parser")
server_parser_p.add_argument("-tcp", help="tcp option")
server_parser_p.add_argument("-fips", help="fips option")
server_parser_p.add_argument("-sim", help="sim option")


args = main_parser.parse_args()  

推荐答案

aparser.add_argument(...)创建一个 Action 类对象，该对象实际上是由 action 参数.该动作/参数可以是 positional 或 optional (已标记).

aparser.add_argument(...) creates an Action class object, actually a subclass specified by the action parameter. That action/argument may be positional or optional (flagged).

sp = aparse.add_subparsers(...)是 add_argument 的专用版本，可创建subparser类的 Action . print(sp)将显示其某些属性.这实际上是带有 choices 属性的 positional 参数.

sp=aparse.add_subparsers(...) is specialized version of add_argument that creates an Action of the subparser class. print(sp) will show some of its attributes. This is actually a positional argument, with a choices attribute.

p1 = sp.add_parser(...)创建一个 argparse.ArgumentParser()对象，并将其链接到放置在中的名称sp.choices 列表.解析器作为 p1 变量返回.

p1 = sp.add_parser(...) creates an argparse.ArgumentParser() object, and links it to a name that is placed in the sp.choices list. The parser is returned as the p1 variable.

p1.add_argument(...)定义一个动作/参数，就像使用主解析器一样.

p1.add_argument(...) defines a Action/argument, just as done with the main parser.

因此，在解析过程中，输入( sys.argv )像往常一样被一个接一个地处理.但是，当它命中位置和名称与"p1"相匹配的字符串时，解析任务将传递给 p1 (剩下的 sys.argv 列表中的内容)).当 p1 到达 sys.argv 的末尾时，其名称空间和控制权将传递给父解析器.父级不做任何进一步的解析.

So during parsing, the inputs (sys.argv) are handled one by one, as is usual. But when it hits a string that matches in position and name of a "p1", the parsing task is passed on to p1 (with what remains of the sys.argv list). When p1 has reached the end of sys.argv its namespace and control is passed to the parent parser. The parent doesn't do any further parsing.

在您的情况下，您可以向下传递多个层次的解析器.(至少在描述中，术语解析器"和子解析器"可能会有些混乱.它们在代码中已明确定义.)

In your case you can pass down through several levels of parsers. (the terms, parser and subparsers can be a bit confusing, at least in the description. They are clearly defined in the code.)

此子解析器机制仅允许一个选择(在每个级别).这不是多级树横向工具.您沿某个特定线程结束，然后返回.

This subparser mechanism allows only one choice (at each level). This isn't a multilevel tree transversal tool. You go down one particular thread to end, and back up.

所以

./buildServer.py Dev arch -arm build -comms或./buildServer.py Dev arch -arm build -server -tcp

./buildServer.py Dev arch -arm build -comms or ./buildServer.py Dev arch -arm build -server -tcp

main_parser   (sees 'Dev', passes control to:)
    dev_parser   (sees 'arch', passes control to:)
        action_arch_parser
            (sees -arm - sets the const)
            (doesn't have any positional to handle 'build'
                  returns with an unrechognized arguments)

可能有一些方法可以解决此问题-我或其他人在以前的SO中曾建议过类似的事情-但直接使用 argparse 不允许有多个子解析器(仅显示的嵌套)).

There may be ways of working around this - I or others have suggested things like this in previous SO - but the straight forward argparse usage does not allow for multiple subparsers (just the nesting that you show).

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