Django커맨드들은 어떻게 만들어지고 어떻게 동작하는가 - [1]

# django/core/managemnet/__init__.py
class ManagementUtility:
    ...
    def execute(self):
        ...
        if subcommand == "help":
            if "--commands" in args:
                sys.stdout.write(self.main_help_text(commands_only=True) + "\n")
            elif not options.args:
                sys.stdout.write(self.main_help_text() + "\n")
            else:
                self.fetch_command(options.args[0]).print_help(
                    self.prog_name, options.args[0]
                )
        # Special-cases: We want 'django-admin --version' and
        # 'django-admin --help' to work, for backwards compatibility.
        elif subcommand == "version" or self.argv[1:] == ["--version"]:
            sys.stdout.write(django.get_version() + "\n")
        elif self.argv[1:] in (["--help"], ["-h"]):
            sys.stdout.write(self.main_help_text() + "\n")
        else:
            self.fetch_command(subcommand).run_from_argv(self.argv)

def get_version(version=None):
    """Return a PEP 440-compliant version number from VERSION."""
    version = get_complete_version(version)

    # Now build the two parts of the version number:
    # main = X.Y[.Z]
    # sub = .devN - for pre-alpha releases
    #     | {a|b|rc}N - for alpha, beta, and rc releases

    main = get_main_version(version)
    sub = ""
    if version[3] == "alpha" and version[4] == 0:
        git_changeset = get_git_changeset()
        if git_changeset:
            sub = ".dev%s" % git_changeset

    elif version[3] != "final":
        mapping = {"alpha": "a", "beta": "b", "rc": "rc"}
        sub = mapping[version[3]] + str(version[4])

    return main + sub

def get_complete_version(version=None):
    """
    Return a tuple of the django version. If version argument is non-empty,
    check for correctness of the tuple provided.
    """
    if version is None:
        from django import VERSION as version
    else:
        assert len(version) == 5
        assert version[3] in ("alpha", "beta", "rc", "final")

    return version

# django

VERSION = (4, 2, 13, "final", 0)

__version__ = get_version(VERSION)
...

# django/core/managemnet/__init__.py
class ManagementUtility:
    ...
    def execute(self):
        ...
        if subcommand == "help":
            if "--commands" in args:
                sys.stdout.write(self.main_help_text(commands_only=True) + "\n")
            elif not options.args:
                sys.stdout.write(self.main_help_text() + "\n")
            else:
                self.fetch_command(options.args[0]).print_help(
                    self.prog_name, options.args[0]
                )
        # Special-cases: We want 'django-admin --version' and
        # 'django-admin --help' to work, for backwards compatibility.
        elif subcommand == "version" or self.argv[1:] == ["--version"]:
            sys.stdout.write(django.get_version() + "\n")
        elif self.argv[1:] in (["--help"], ["-h"]):
            sys.stdout.write(self.main_help_text() + "\n")
        else:
            self.fetch_command(subcommand).run_from_argv(self.argv)

class ManagementUtility:
    ...
    def fetch_command(self, subcommand):
        """
        Try to fetch the given subcommand, printing a message with the
        appropriate command called from the command line (usually
        "django-admin" or "manage.py") if it can't be found.
        """
        # Get commands outside of try block to prevent swallowing exceptions
        commands = get_commands()
        try:
            app_name = commands[subcommand]
        except KeyError:
            if os.environ.get("DJANGO_SETTINGS_MODULE"):
                # If `subcommand` is missing due to misconfigured settings, the
                # following line will retrigger an ImproperlyConfigured exception
                # (get_commands() swallows the original one) so the user is
                # informed about it.
                settings.INSTALLED_APPS
            elif not settings.configured:
                sys.stderr.write("No Django settings specified.\n")
            possible_matches = get_close_matches(subcommand, commands)
            sys.stderr.write("Unknown command: %r" % subcommand)
            if possible_matches:
                sys.stderr.write(". Did you mean %s?" % possible_matches[0])
            sys.stderr.write("\nType '%s help' for usage.\n" % self.prog_name)
            sys.exit(1)
        if isinstance(app_name, BaseCommand):
            # If the command is already loaded, use it directly.
            klass = app_name
        else:
            klass = load_command_class(app_name, subcommand)
        return klass
    ...

class ManagementUtility:
    ...
    def fetch_command(self, subcommand):
        try:
            app_name = commands[subcommand]
        except KeyError:
            if os.environ.get("DJANGO_SETTINGS_MODULE"):
                # If `subcommand` is missing due to misconfigured settings, the
                # following line will retrigger an ImproperlyConfigured exception
                # (get_commands() swallows the original one) so the user is
                # informed about it.
                settings.INSTALLED_APPS
            elif not settings.configured:
                sys.stderr.write("No Django settings specified.\n")
            possible_matches = get_close_matches(subcommand, commands)
            sys.stderr.write("Unknown command: %r" % subcommand)
            if possible_matches:
                sys.stderr.write(". Did you mean %s?" % possible_matches[0])
            sys.stderr.write("\nType '%s help' for usage.\n" % self.prog_name)
            sys.exit(1)
        if isinstance(app_name, BaseCommand):
            # If the command is already loaded, use it directly.
            klass = app_name
        else:
            klass = load_command_class(app_name, subcommand)
        return klass
    ...

class ManagementUtility:
    ...
    def fetch_command(self, subcommand):
        try:
            app_name = commands[subcommand]
        except KeyError:
            ...
        if isinstance(app_name, BaseCommand):
            # If the command is already loaded, use it directly.
            klass = app_name
        else:
            klass = load_command_class(app_name, subcommand)
        return klass
    ...

def load_command_class(app_name, name):
    """
    Given a command name and an application name, return the Command
    class instance. Allow all errors raised by the import process
    (ImportError, AttributeError) to propagate.
    """
    module = import_module("%s.management.commands.%s" % (app_name, name))
    return module.Command()

def load_command_class(app_name, name):
    """
    Given a command name and an application name, return the Command
    class instance. Allow all errors raised by the import process
    (ImportError, AttributeError) to propagate.
    """
    module = import_module("%s.management.commands.%s" % (app_name, name))
    return module.Command()

class ManagementUtility:
    ...
    def fetch_command(self, subcommand):
        if isinstance(app_name, BaseCommand):
            # If the command is already loaded, use it directly.
            klass = app_name
        else:
            klass = load_command_class(app_name, subcommand)
        return klass
    ...

class ManagementUtility:
    ...
    def execute(self):
        ...
        if subcommand == "help":
            if "--commands" in args:
                ...
        # Special-cases: We want 'django-admin --version' and
        # 'django-admin --help' to work, for backwards compatibility.
        elif subcommand == "version" or self.argv[1:] == ["--version"]:
            sys.stdout.write(django.get_version() + "\n")
        elif self.argv[1:] in (["--help"], ["-h"]):
            sys.stdout.write(self.main_help_text() + "\n")
        else:
            self.fetch_command(subcommand).run_from_argv(self.argv)

class BaseCommand:
    ...
    def run_from_argv(self, argv):
        """
        Set up any environment changes requested (e.g., Python path
        and Django settings), then run this command. If the
        command raises a ``CommandError``, intercept it and print it sensibly
        to stderr. If the ``--traceback`` option is present or the raised
        ``Exception`` is not ``CommandError``, raise it.
        """
        self._called_from_command_line = True
        parser = self.create_parser(argv[0], argv[1])

        options = parser.parse_args(argv[2:])
        cmd_options = vars(options)
        # Move positional args out of options to mimic legacy optparse
        args = cmd_options.pop("args", ())
        handle_default_options(options)
        try:
            self.execute(*args, **cmd_options)
        except CommandError as e:
            if options.traceback:
                raise

            # SystemCheckError takes care of its own formatting.
            if isinstance(e, SystemCheckError):
                self.stderr.write(str(e), lambda x: x)
            else:
                self.stderr.write("%s: %s" % (e.__class__.__name__, e))
            sys.exit(e.returncode)
        finally:
            try:
                connections.close_all()
            except ImproperlyConfigured:
                # Ignore if connections aren't setup at this point (e.g. no
                # configured settings).
                pass
    ...

class BaseCommand:
    ...
    def create_parser(self, prog_name, subcommand, **kwargs):
        """
        Create and return the ``ArgumentParser`` which will be used to
        parse the arguments to this command.
        """
        kwargs.setdefault("formatter_class", DjangoHelpFormatter)
        parser = CommandParser(
            prog="%s %s" % (os.path.basename(prog_name), subcommand),
            description=self.help or None,
            missing_args_message=getattr(self, "missing_args_message", None),
            called_from_command_line=getattr(self, "_called_from_command_line", None),
            **kwargs,
        )

from django.core.management.base import BaseCommand

class Command(BaseCommand):
  
  def add_arguments(self, parser):
    parser.add_argument(
      "--hello",
      action="store_true",
      help=(
        "Add 'hello' to the output."
      )
    )
    parser.add_argument(
      "--world",
      action="store_true",
      help=(
        "Add 'world' to the output."
      )
    )
    
  
  def handle(self, *app_labels, **options):
    return self.stdout.write("run test1 command!!" + "\n")

class BaseCommand:
    ...
    def create_parser(self, prog_name, subcommand, **kwargs):
        """
        Create and return the ``ArgumentParser`` which will be used to
        parse the arguments to this command.
        """
        ...
        self.add_base_argument(
            parser,
            "--version",
            action="version",
            version=self.get_version(),
            help="Show program's version number and exit.",
        )
        self.add_base_argument(
            parser,
            "-v",
            "--verbosity",
            default=1,
            type=int,
            choices=[0, 1, 2, 3],
            help=(
                "Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, "
                "3=very verbose output"
            ),
        )
        self.add_base_argument(
            parser,
            "--settings",
            help=(
                "The Python path to a settings module, e.g. "
                '"myproject.settings.main". If this isn\'t provided, the '
                "DJANGO_SETTINGS_MODULE environment variable will be used."
            ),
        )
        self.add_base_argument(
            parser,
            "--pythonpath",
            help=(
                "A directory to add to the Python path, e.g. "
                '"/home/djangoprojects/myproject".'
            ),
        )
        self.add_base_argument(
            parser,
            "--traceback",
            action="store_true",
            help="Raise on CommandError exceptions.",
        )
        self.add_base_argument(
            parser,
            "--no-color",
            action="store_true",
            help="Don't colorize the command output.",
        )
        self.add_base_argument(
            parser,
            "--force-color",
            action="store_true",
            help="Force colorization of the command output.",
        )
        if self.requires_system_checks:
            parser.add_argument(
                "--skip-checks",
                action="store_true",
                help="Skip system checks.",
            )
        self.add_arguments(parser)
        return parser

class BaseCommand:
    ...
    def add_base_argument(self, parser, *args, **kwargs):
        """
        Call the parser's add_argument() method, suppressing the help text
        according to BaseCommand.suppressed_base_arguments.
        """
        
        for arg in args:
            if arg in self.suppressed_base_arguments:
                kwargs["help"] = argparse.SUPPRESS
                break
        parser.add_argument(*args, **kwargs)

class Command(BaseCommand):
  
  def __init__(self):
    self.suppressed_base_arguments.add('--no-color')
    self.suppressed_base_arguments.add('--force-color')
    super().__init__()
  ...

class BaseCommand:
    ...
    def create_parser(self, prog_name, subcommand, **kwargs):
        """
        Create and return the ``ArgumentParser`` which will be used to
        parse the arguments to this command.
        """
        ...
        if self.requires_system_checks:
            parser.add_argument(
                "--skip-checks",
                action="store_true",
                help="Skip system checks.",
            )
        self.add_arguments(parser)
        return parser

class CommandParser(ArgumentParser):
    def parse_args(self, args=None, namespace=None):
        # Catch missing argument for a better error message
        if self.missing_args_message and not (
            args or any(not arg.startswith("-") for arg in args)
        ):
            self.error(self.missing_args_message)
        return super().parse_args(args, namespace)

class Command(BaseCommand):
  
  def __init__(self):
    self.suppressed_base_arguments.add('--no-color')
    self.suppressed_base_arguments.add('--force-color')
    self.missing_args_message = "!!!!!!!!!!!!!"
    super().__init__()
  ...

class BaseCommand():
    def run_from_argv(self, argv):
        ...
        options = parser.parse_args(argv[2:])
        cmd_options = vars(options)
        # Move positional args out of options to mimic legacy optparse
        args = cmd_options.pop("args", ())
        handle_default_options(options)
        try:
            self.execute(*args, **cmd_options)

class BaseCommand:
    ...
    def execute(self, *args, **options):
        """
        Try to execute this command, performing system checks if needed (as
        controlled by the ``requires_system_checks`` attribute, except if
        force-skipped).
        """
        if options["force_color"] and options["no_color"]:
            raise CommandError(
                "The --no-color and --force-color options can't be used together."
            )
        if options["force_color"]:
            self.style = color_style(force_color=True)
        elif options["no_color"]:
            self.style = no_style()
            self.stderr.style_func = None
        if options.get("stdout"):
            self.stdout = OutputWrapper(options["stdout"])
        if options.get("stderr"):
            self.stderr = OutputWrapper(options["stderr"])

class BaseCommand():
    ...
    def execute(self, *args, **options):
        ...
        if self.requires_system_checks and not options["skip_checks"]:
            if self.requires_system_checks == ALL_CHECKS:
                self.check()
            else:
                self.check(tags=self.requires_system_checks)
        if self.requires_migrations_checks:
            self.check_migrations()
        output = self.handle(*args, **options)

class BaseCommand():
    def check(
        self,
        app_configs=None,
        tags=None,
        display_num_errors=False,
        include_deployment_checks=False,
        fail_level=checks.ERROR,
        databases=None,
    ):
        """
        Use the system check framework to validate entire Django project.
        Raise CommandError for any serious message (error or critical errors).
        If there are only light messages (like warnings), print them to stderr
        and don't raise an exception.
        """
        all_issues = checks.run_checks(
            app_configs=app_configs,
            tags=tags,
            include_deployment_checks=include_deployment_checks,
            databases=databases,
        )

        header, body, footer = "", "", ""
        visible_issue_count = 0  # excludes silenced warnings

        if all_issues:
            debugs = [
                e for e in all_issues if e.level < checks.INFO and not e.is_silenced()
            ]
            infos = [
                e
                for e in all_issues
                if checks.INFO <= e.level < checks.WARNING and not e.is_silenced()
            ]
            warnings = [
                e
                for e in all_issues
                if checks.WARNING <= e.level < checks.ERROR and not e.is_silenced()
            ]
            errors = [
                e
                for e in all_issues
                if checks.ERROR <= e.level < checks.CRITICAL and not e.is_silenced()
            ]
            criticals = [
                e
                for e in all_issues
                if checks.CRITICAL <= e.level and not e.is_silenced()
            ]
            sorted_issues = [
                (criticals, "CRITICALS"),
                (errors, "ERRORS"),
                (warnings, "WARNINGS"),
                (infos, "INFOS"),
                (debugs, "DEBUGS"),
            ]

            for issues, group_name in sorted_issues:
                if issues:
                    visible_issue_count += len(issues)
                    formatted = (
                        self.style.ERROR(str(e))
                        if e.is_serious()
                        else self.style.WARNING(str(e))
                        for e in issues
                    )
                    formatted = "\n".join(sorted(formatted))
                    body += "\n%s:\n%s\n" % (group_name, formatted)

        if visible_issue_count:
            header = "System check identified some issues:\n"

        if display_num_errors:
            if visible_issue_count:
                footer += "\n"
            footer += "System check identified %s (%s silenced)." % (
                "no issues"
                if visible_issue_count == 0
                else "1 issue"
                if visible_issue_count == 1
                else "%s issues" % visible_issue_count,
                len(all_issues) - visible_issue_count,
            )

        if any(e.is_serious(fail_level) and not e.is_silenced() for e in all_issues):
            msg = self.style.ERROR("SystemCheckError: %s" % header) + body + footer
            raise SystemCheckError(msg)
        else:
            msg = header + body + footer

        if msg:
            if visible_issue_count:
                self.stderr.write(msg, lambda x: x)
            else:
                self.stdout.write(msg)

from django.core import CheckRegistry

def my_check():
    pass

registry = CheckRegistry()

1. registry.register(my_check, 'mytag', 'anothertag')
2. @registry.register('mytag', 'anothertag')

class BaseCommand():
    ...
    def execute(self, *args, **options):
        ...
        if self.requires_system_checks and not options["skip_checks"]:
            if self.requires_system_checks == ALL_CHECKS:
                self.check()
            else:
                self.check(tags=self.requires_system_checks)
        if self.requires_migrations_checks:
            self.check_migrations()
        output = self.handle(*args, **options)

from django.core.management.base import BaseCommand

class Command(BaseCommand):
  
  def __init__(self):
    # self.suppressed_base_arguments.add('--no-color')
    # self.suppressed_base_arguments.add('--force-color')
    # self.missing_args_message = "!!!!!!!!!!!!!"
    super().__init__()
  
  def add_arguments(self, parser):
    parser.add_argument(
      "--hello",
      action="store_true",
      help=(
        "Add 'hello' to the output."
      )
    )
    parser.add_argument(
      "--world",
      action="store_true",
      help=(
        "Add 'world' to the output."
      )
    )
    
  
  def handle(self, *app_labels, **options):
    return self.stdout.write("run test1 command!!" + "\n")