initial import of the packaging package in the standard library

1 files changed, 819 insertions, 0 deletions

diff --git a/Lib/packaging/dist.py b/Lib/packaging/dist.py
new file mode 100644
index 0000000..6065e78
--- /dev/null
+++ b/Lib/packaging/dist.py
@@ -0,0 +1,819 @@
+"""Class representing the distribution being built/installed/etc."""
+
+import os
+import re
+
+from packaging.errors import (PackagingOptionError, PackagingArgError,
+                              PackagingModuleError, PackagingClassError)
+from packaging.fancy_getopt import FancyGetopt
+from packaging.util import strtobool, resolve_name
+from packaging import logger
+from packaging.metadata import Metadata
+from packaging.config import Config
+from packaging.command import get_command_class, STANDARD_COMMANDS
+
+# Regex to define acceptable Packaging command names.  This is not *quite*
+# the same as a Python NAME -- I don't allow leading underscores.  The fact
+# that they're very similar is no coincidence; the default naming scheme is
+# to look for a Python module named after the command.
+command_re = re.compile(r'^[a-zA-Z]([a-zA-Z0-9_]*)$')
+
+USAGE = """\
+usage: %(script)s [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
+   or: %(script)s --help [cmd1 cmd2 ...]
+   or: %(script)s --help-commands
+   or: %(script)s cmd --help
+"""
+
+
+def gen_usage(script_name):
+    script = os.path.basename(script_name)
+    return USAGE % {'script': script}
+
+
+class Distribution:
+    """The core of the Packaging.  Most of the work hiding behind 'setup'
+    is really done within a Distribution instance, which farms the work out
+    to the Packaging commands specified on the command line.
+
+    Setup scripts will almost never instantiate Distribution directly,
+    unless the 'setup()' function is totally inadequate to their needs.
+    However, it is conceivable that a setup script might wish to subclass
+    Distribution for some specialized purpose, and then pass the subclass
+    to 'setup()' as the 'distclass' keyword argument.  If so, it is
+    necessary to respect the expectations that 'setup' has of Distribution.
+    See the code for 'setup()', in run.py, for details.
+    """
+
+    # 'global_options' describes the command-line options that may be
+    # supplied to the setup script prior to any actual commands.
+    # Eg. "./setup.py -n" or "./setup.py --dry-run" both take advantage of
+    # these global options.  This list should be kept to a bare minimum,
+    # since every global option is also valid as a command option -- and we
+    # don't want to pollute the commands with too many options that they
+    # have minimal control over.
+    global_options = [
+        ('dry-run', 'n', "don't actually do anything"),
+        ('help', 'h', "show detailed help message"),
+        ('no-user-cfg', None, 'ignore pydistutils.cfg in your home directory'),
+    ]
+
+    # 'common_usage' is a short (2-3 line) string describing the common
+    # usage of the setup script.
+    common_usage = """\
+Common commands: (see '--help-commands' for more)
+
+  setup.py build      will build the package underneath 'build/'
+  setup.py install    will install the package
+"""
+
+    # options that are not propagated to the commands
+    display_options = [
+        ('help-commands', None,
+         "list all available commands"),
+        ('name', None,
+         "print package name"),
+        ('version', 'V',
+         "print package version"),
+        ('fullname', None,
+         "print <package name>-<version>"),
+        ('author', None,
+         "print the author's name"),
+        ('author-email', None,
+         "print the author's email address"),
+        ('maintainer', None,
+         "print the maintainer's name"),
+        ('maintainer-email', None,
+         "print the maintainer's email address"),
+        ('contact', None,
+         "print the maintainer's name if known, else the author's"),
+        ('contact-email', None,
+         "print the maintainer's email address if known, else the author's"),
+        ('url', None,
+         "print the URL for this package"),
+        ('license', None,
+         "print the license of the package"),
+        ('licence', None,
+         "alias for --license"),
+        ('description', None,
+         "print the package description"),
+        ('long-description', None,
+         "print the long package description"),
+        ('platforms', None,
+         "print the list of platforms"),
+        ('classifier', None,
+         "print the list of classifiers"),
+        ('keywords', None,
+         "print the list of keywords"),
+        ('provides', None,
+         "print the list of packages/modules provided"),
+        ('requires', None,
+         "print the list of packages/modules required"),
+        ('obsoletes', None,
+         "print the list of packages/modules made obsolete"),
+        ('use-2to3', None,
+         "use 2to3 to make source python 3.x compatible"),
+        ('convert-2to3-doctests', None,
+         "use 2to3 to convert doctests in seperate text files"),
+        ]
+    display_option_names = [x[0].replace('-', '_') for x in display_options]
+
+    # negative options are options that exclude other options
+    negative_opt = {}
+
+    # -- Creation/initialization methods -------------------------------
+    def __init__(self, attrs=None):
+        """Construct a new Distribution instance: initialize all the
+        attributes of a Distribution, and then use 'attrs' (a dictionary
+        mapping attribute names to values) to assign some of those
+        attributes their "real" values.  (Any attributes not mentioned in
+        'attrs' will be assigned to some null value: 0, None, an empty list
+        or dictionary, etc.)  Most importantly, initialize the
+        'command_obj' attribute to the empty dictionary; this will be
+        filled in with real command objects by 'parse_command_line()'.
+        """
+
+        # Default values for our command-line options
+        self.dry_run = False
+        self.help = False
+        for attr in self.display_option_names:
+            setattr(self, attr, False)
+
+        # Store the configuration
+        self.config = Config(self)
+
+        # Store the distribution metadata (name, version, author, and so
+        # forth) in a separate object -- we're getting to have enough
+        # information here (and enough command-line options) that it's
+        # worth it.
+        self.metadata = Metadata()
+
+        # 'cmdclass' maps command names to class objects, so we
+        # can 1) quickly figure out which class to instantiate when
+        # we need to create a new command object, and 2) have a way
+        # for the setup script to override command classes
+        self.cmdclass = {}
+
+        # 'script_name' and 'script_args' are usually set to sys.argv[0]
+        # and sys.argv[1:], but they can be overridden when the caller is
+        # not necessarily a setup script run from the command line.
+        self.script_name = None
+        self.script_args = None
+
+        # 'command_options' is where we store command options between
+        # parsing them (from config files, the command line, etc.) and when
+        # they are actually needed -- ie. when the command in question is
+        # instantiated.  It is a dictionary of dictionaries of 2-tuples:
+        #   command_options = { command_name : { option : (source, value) } }
+        self.command_options = {}
+
+        # 'dist_files' is the list of (command, pyversion, file) that
+        # have been created by any dist commands run so far. This is
+        # filled regardless of whether the run is dry or not. pyversion
+        # gives sysconfig.get_python_version() if the dist file is
+        # specific to a Python version, 'any' if it is good for all
+        # Python versions on the target platform, and '' for a source
+        # file. pyversion should not be used to specify minimum or
+        # maximum required Python versions; use the metainfo for that
+        # instead.
+        self.dist_files = []
+
+        # These options are really the business of various commands, rather
+        # than of the Distribution itself.  We provide aliases for them in
+        # Distribution as a convenience to the developer.
+        self.packages = []
+        self.package_data = {}
+        self.package_dir = None
+        self.py_modules = []
+        self.libraries = []
+        self.headers = []
+        self.ext_modules = []
+        self.ext_package = None
+        self.include_dirs = []
+        self.extra_path = None
+        self.scripts = []
+        self.data_files = {}
+        self.password = ''
+        self.use_2to3 = False
+        self.convert_2to3_doctests = []
+        self.extra_files = []
+
+        # And now initialize bookkeeping stuff that can't be supplied by
+        # the caller at all.  'command_obj' maps command names to
+        # Command instances -- that's how we enforce that every command
+        # class is a singleton.
+        self.command_obj = {}
+
+        # 'have_run' maps command names to boolean values; it keeps track
+        # of whether we have actually run a particular command, to make it
+        # cheap to "run" a command whenever we think we might need to -- if
+        # it's already been done, no need for expensive filesystem
+        # operations, we just check the 'have_run' dictionary and carry on.
+        # It's only safe to query 'have_run' for a command class that has
+        # been instantiated -- a false value will be inserted when the
+        # command object is created, and replaced with a true value when
+        # the command is successfully run.  Thus it's probably best to use
+        # '.get()' rather than a straight lookup.
+        self.have_run = {}
+
+        # Now we'll use the attrs dictionary (ultimately, keyword args from
+        # the setup script) to possibly override any or all of these
+        # distribution options.
+
+        if attrs is not None:
+            # Pull out the set of command options and work on them
+            # specifically.  Note that this order guarantees that aliased
+            # command options will override any supplied redundantly
+            # through the general options dictionary.
+            options = attrs.get('options')
+            if options is not None:
+                del attrs['options']
+                for command, cmd_options in options.items():
+                    opt_dict = self.get_option_dict(command)
+                    for opt, val in cmd_options.items():
+                        opt_dict[opt] = ("setup script", val)
+
+            # Now work on the rest of the attributes.  Any attribute that's
+            # not already defined is invalid!
+            for key, val in attrs.items():
+                if self.metadata.is_metadata_field(key):
+                    self.metadata[key] = val
+                elif hasattr(self, key):
+                    setattr(self, key, val)
+                else:
+                    logger.warning(
+                        'unknown argument given to Distribution: %r', key)
+
+        # no-user-cfg is handled before other command line args
+        # because other args override the config files, and this
+        # one is needed before we can load the config files.
+        # If attrs['script_args'] wasn't passed, assume false.
+        #
+        # This also make sure we just look at the global options
+        self.want_user_cfg = True
+
+        if self.script_args is not None:
+            for arg in self.script_args:
+                if not arg.startswith('-'):
+                    break
+                if arg == '--no-user-cfg':
+                    self.want_user_cfg = False
+                    break
+
+        self.finalize_options()
+
+    def get_option_dict(self, command):
+        """Get the option dictionary for a given command.  If that
+        command's option dictionary hasn't been created yet, then create it
+        and return the new dictionary; otherwise, return the existing
+        option dictionary.
+        """
+        d = self.command_options.get(command)
+        if d is None:
+            d = self.command_options[command] = {}
+        return d
+
+    def get_fullname(self):
+        return self.metadata.get_fullname()
+
+    def dump_option_dicts(self, header=None, commands=None, indent=""):
+        from pprint import pformat
+
+        if commands is None:             # dump all command option dicts
+            commands = sorted(self.command_options)
+
+        if header is not None:
+            logger.info(indent + header)
+            indent = indent + "  "
+
+        if not commands:
+            logger.info(indent + "no commands known yet")
+            return
+
+        for cmd_name in commands:
+            opt_dict = self.command_options.get(cmd_name)
+            if opt_dict is None:
+                logger.info(indent + "no option dict for %r command",
+                            cmd_name)
+            else:
+                logger.info(indent + "option dict for %r command:", cmd_name)
+                out = pformat(opt_dict)
+                for line in out.split('\n'):
+                    logger.info(indent + "  " + line)
+
+    # -- Config file finding/parsing methods ---------------------------
+    # XXX to be removed
+    def parse_config_files(self, filenames=None):
+        return self.config.parse_config_files(filenames)
+
+    def find_config_files(self):
+        return self.config.find_config_files()
+
+    # -- Command-line parsing methods ----------------------------------
+
+    def parse_command_line(self):
+        """Parse the setup script's command line, taken from the
+        'script_args' instance attribute (which defaults to 'sys.argv[1:]'
+        -- see 'setup()' in run.py).  This list is first processed for
+        "global options" -- options that set attributes of the Distribution
+        instance.  Then, it is alternately scanned for Packaging commands
+        and options for that command.  Each new command terminates the
+        options for the previous command.  The allowed options for a
+        command are determined by the 'user_options' attribute of the
+        command class -- thus, we have to be able to load command classes
+        in order to parse the command line.  Any error in that 'options'
+        attribute raises PackagingGetoptError; any error on the
+        command line raises PackagingArgError.  If no Packaging commands
+        were found on the command line, raises PackagingArgError.  Return
+        true if command line was successfully parsed and we should carry
+        on with executing commands; false if no errors but we shouldn't
+        execute commands (currently, this only happens if user asks for
+        help).
+        """
+        #
+        # We now have enough information to show the Macintosh dialog
+        # that allows the user to interactively specify the "command line".
+        #
+        toplevel_options = self._get_toplevel_options()
+
+        # We have to parse the command line a bit at a time -- global
+        # options, then the first command, then its options, and so on --
+        # because each command will be handled by a different class, and
+        # the options that are valid for a particular class aren't known
+        # until we have loaded the command class, which doesn't happen
+        # until we know what the command is.
+
+        self.commands = []
+        parser = FancyGetopt(toplevel_options + self.display_options)
+        parser.set_negative_aliases(self.negative_opt)
+        parser.set_aliases({'licence': 'license'})
+        args = parser.getopt(args=self.script_args, object=self)
+        option_order = parser.get_option_order()
+
+        # for display options we return immediately
+        if self.handle_display_options(option_order):
+            return
+
+        while args:
+            args = self._parse_command_opts(parser, args)
+            if args is None:            # user asked for help (and got it)
+                return
+
+        # Handle the cases of --help as a "global" option, ie.
+        # "setup.py --help" and "setup.py --help command ...".  For the
+        # former, we show global options (--dry-run, etc.)
+        # and display-only options (--name, --version, etc.); for the
+        # latter, we omit the display-only options and show help for
+        # each command listed on the command line.
+        if self.help:
+            self._show_help(parser,
+                            display_options=len(self.commands) == 0,
+                            commands=self.commands)
+            return
+
+        return 1
+
+    def _get_toplevel_options(self):
+        """Return the non-display options recognized at the top level.
+
+        This includes options that are recognized *only* at the top
+        level as well as options recognized for commands.
+        """
+        return self.global_options
+
+    def _parse_command_opts(self, parser, args):
+        """Parse the command-line options for a single command.
+        'parser' must be a FancyGetopt instance; 'args' must be the list
+        of arguments, starting with the current command (whose options
+        we are about to parse).  Returns a new version of 'args' with
+        the next command at the front of the list; will be the empty
+        list if there are no more commands on the command line.  Returns
+        None if the user asked for help on this command.
+        """
+        # Pull the current command from the head of the command line
+        command = args[0]
+        if not command_re.match(command):
+            raise SystemExit("invalid command name %r" % command)
+        self.commands.append(command)
+
+        # Dig up the command class that implements this command, so we
+        # 1) know that it's a valid command, and 2) know which options
+        # it takes.
+        try:
+            cmd_class = get_command_class(command)
+        except PackagingModuleError as msg:
+            raise PackagingArgError(msg)
+
+        # XXX We want to push this in packaging.command
+        #
+        # Require that the command class be derived from Command -- want
+        # to be sure that the basic "command" interface is implemented.
+        for meth in ('initialize_options', 'finalize_options', 'run'):
+            if hasattr(cmd_class, meth):
+                continue
+            raise PackagingClassError(
+                'command %r must implement %r' % (cmd_class, meth))
+
+        # Also make sure that the command object provides a list of its
+        # known options.
+        if not (hasattr(cmd_class, 'user_options') and
+                isinstance(cmd_class.user_options, list)):
+            raise PackagingClassError(
+                "command class %s must provide "
+                "'user_options' attribute (a list of tuples)" % cmd_class)
+
+        # If the command class has a list of negative alias options,
+        # merge it in with the global negative aliases.
+        negative_opt = self.negative_opt
+        if hasattr(cmd_class, 'negative_opt'):
+            negative_opt = negative_opt.copy()
+            negative_opt.update(cmd_class.negative_opt)
+
+        # Check for help_options in command class.  They have a different
+        # format (tuple of four) so we need to preprocess them here.
+        if (hasattr(cmd_class, 'help_options') and
+            isinstance(cmd_class.help_options, list)):
+            help_options = cmd_class.help_options[:]
+        else:
+            help_options = []
+
+        # All commands support the global options too, just by adding
+        # in 'global_options'.
+        parser.set_option_table(self.global_options +
+                                cmd_class.user_options +
+                                help_options)
+        parser.set_negative_aliases(negative_opt)
+        args, opts = parser.getopt(args[1:])
+        if hasattr(opts, 'help') and opts.help:
+            self._show_help(parser, display_options=False,
+                            commands=[cmd_class])
+            return
+
+        if (hasattr(cmd_class, 'help_options') and
+            isinstance(cmd_class.help_options, list)):
+            help_option_found = False
+            for help_option, short, desc, func in cmd_class.help_options:
+                if hasattr(opts, help_option.replace('-', '_')):
+                    help_option_found = True
+                    if hasattr(func, '__call__'):
+                        func()
+                    else:
+                        raise PackagingClassError(
+                            "invalid help function %r for help option %r: "
+                            "must be a callable object (function, etc.)"
+                            % (func, help_option))
+
+            if help_option_found:
+                return
+
+        # Put the options from the command line into their official
+        # holding pen, the 'command_options' dictionary.
+        opt_dict = self.get_option_dict(command)
+        for name, value in vars(opts).items():
+            opt_dict[name] = ("command line", value)
+
+        return args
+
+    def finalize_options(self):
+        """Set final values for all the options on the Distribution
+        instance, analogous to the .finalize_options() method of Command
+        objects.
+        """
+        if getattr(self, 'convert_2to3_doctests', None):
+            self.convert_2to3_doctests = [os.path.join(p)
+                                for p in self.convert_2to3_doctests]
+        else:
+            self.convert_2to3_doctests = []
+
+    def _show_help(self, parser, global_options=True, display_options=True,
+                   commands=[]):
+        """Show help for the setup script command line in the form of
+        several lists of command-line options.  'parser' should be a
+        FancyGetopt instance; do not expect it to be returned in the
+        same state, as its option table will be reset to make it
+        generate the correct help text.
+
+        If 'global_options' is true, lists the global options:
+        --dry-run, etc.  If 'display_options' is true, lists
+        the "display-only" options: --name, --version, etc.  Finally,
+        lists per-command help for every command name or command class
+        in 'commands'.
+        """
+        # late import because of mutual dependence between these modules
+        from packaging.command.cmd import Command
+
+        if global_options:
+            if display_options:
+                options = self._get_toplevel_options()
+            else:
+                options = self.global_options
+            parser.set_option_table(options)
+            parser.print_help(self.common_usage + "\nGlobal options:")
+            print('')
+
+        if display_options:
+            parser.set_option_table(self.display_options)
+            parser.print_help(
+                "Information display options (just display " +
+                "information, ignore any commands)")
+            print('')
+
+        for command in self.commands:
+            if isinstance(command, type) and issubclass(command, Command):
+                cls = command
+            else:
+                cls = get_command_class(command)
+            if (hasattr(cls, 'help_options') and
+                isinstance(cls.help_options, list)):
+                parser.set_option_table(cls.user_options + cls.help_options)
+            else:
+                parser.set_option_table(cls.user_options)
+            parser.print_help("Options for %r command:" % cls.__name__)
+            print('')
+
+        print(gen_usage(self.script_name))
+
+    def handle_display_options(self, option_order):
+        """If there were any non-global "display-only" options
+        (--help-commands or the metadata display options) on the command
+        line, display the requested info and return true; else return
+        false.
+        """
+        # User just wants a list of commands -- we'll print it out and stop
+        # processing now (ie. if they ran "setup --help-commands foo bar",
+        # we ignore "foo bar").
+        if self.help_commands:
+            self.print_commands()
+            print('')
+            print(gen_usage(self.script_name))
+            return 1
+
+        # If user supplied any of the "display metadata" options, then
+        # display that metadata in the order in which the user supplied the
+        # metadata options.
+        any_display_options = False
+        is_display_option = set()
+        for option in self.display_options:
+            is_display_option.add(option[0])
+
+        for opt, val in option_order:
+            if val and opt in is_display_option:
+                opt = opt.replace('-', '_')
+                value = self.metadata[opt]
+                if opt in ('keywords', 'platform'):
+                    print(','.join(value))
+                elif opt in ('classifier', 'provides', 'requires',
+                             'obsoletes'):
+                    print('\n'.join(value))
+                else:
+                    print(value)
+                any_display_options = True
+
+        return any_display_options
+
+    def print_command_list(self, commands, header, max_length):
+        """Print a subset of the list of all commands -- used by
+        'print_commands()'.
+        """
+        print(header + ":")
+
+        for cmd in commands:
+            cls = self.cmdclass.get(cmd) or get_command_class(cmd)
+            description = getattr(cls, 'description',
+                                  '(no description available)')
+
+            print("  %-*s  %s" % (max_length, cmd, description))
+
+    def _get_command_groups(self):
+        """Helper function to retrieve all the command class names divided
+        into standard commands (listed in
+        packaging2.command.STANDARD_COMMANDS) and extra commands (given in
+        self.cmdclass and not standard commands).
+        """
+        extra_commands = [cmd for cmd in self.cmdclass
+                          if cmd not in STANDARD_COMMANDS]
+        return STANDARD_COMMANDS, extra_commands
+
+    def print_commands(self):
+        """Print out a help message listing all available commands with a
+        description of each.  The list is divided into standard commands
+        (listed in packaging2.command.STANDARD_COMMANDS) and extra commands
+        (given in self.cmdclass and not standard commands).  The
+        descriptions come from the command class attribute
+        'description'.
+        """
+        std_commands, extra_commands = self._get_command_groups()
+        max_length = 0
+        for cmd in (std_commands + extra_commands):
+            if len(cmd) > max_length:
+                max_length = len(cmd)
+
+        self.print_command_list(std_commands,
+                                "Standard commands",
+                                max_length)
+        if extra_commands:
+            print()
+            self.print_command_list(extra_commands,
+                                    "Extra commands",
+                                    max_length)
+
+    # -- Command class/object methods ----------------------------------
+
+    def get_command_obj(self, command, create=True):
+        """Return the command object for 'command'.  Normally this object
+        is cached on a previous call to 'get_command_obj()'; if no command
+        object for 'command' is in the cache, then we either create and
+        return it (if 'create' is true) or return None.
+        """
+        cmd_obj = self.command_obj.get(command)
+        if not cmd_obj and create:
+            logger.debug("Distribution.get_command_obj(): " \
+                         "creating %r command object", command)
+
+            cls = get_command_class(command)
+            cmd_obj = self.command_obj[command] = cls(self)
+            self.have_run[command] = 0
+
+            # Set any options that were supplied in config files
+            # or on the command line.  (NB. support for error
+            # reporting is lame here: any errors aren't reported
+            # until 'finalize_options()' is called, which means
+            # we won't report the source of the error.)
+            options = self.command_options.get(command)
+            if options:
+                self._set_command_options(cmd_obj, options)
+
+        return cmd_obj
+
+    def _set_command_options(self, command_obj, option_dict=None):
+        """Set the options for 'command_obj' from 'option_dict'.  Basically
+        this means copying elements of a dictionary ('option_dict') to
+        attributes of an instance ('command').
+
+        'command_obj' must be a Command instance.  If 'option_dict' is not
+        supplied, uses the standard option dictionary for this command
+        (from 'self.command_options').
+        """
+        command_name = command_obj.get_command_name()
+        if option_dict is None:
+            option_dict = self.get_option_dict(command_name)
+
+        logger.debug("  setting options for %r command:", command_name)
+
+        for option, (source, value) in option_dict.items():
+            logger.debug("    %s = %s (from %s)", option, value, source)
+            try:
+                bool_opts = [x.replace('-', '_')
+                             for x in command_obj.boolean_options]
+            except AttributeError:
+                bool_opts = []
+            try:
+                neg_opt = command_obj.negative_opt
+            except AttributeError:
+                neg_opt = {}
+
+            try:
+                is_string = isinstance(value, str)
+                if option in neg_opt and is_string:
+                    setattr(command_obj, neg_opt[option], not strtobool(value))
+                elif option in bool_opts and is_string:
+                    setattr(command_obj, option, strtobool(value))
+                elif hasattr(command_obj, option):
+                    setattr(command_obj, option, value)
+                else:
+                    raise PackagingOptionError(
+                        "error in %s: command %r has no such option %r" %
+                        (source, command_name, option))
+            except ValueError as msg:
+                raise PackagingOptionError(msg)
+
+    def get_reinitialized_command(self, command, reinit_subcommands=False):
+        """Reinitializes a command to the state it was in when first
+        returned by 'get_command_obj()': ie., initialized but not yet
+        finalized.  This provides the opportunity to sneak option
+        values in programmatically, overriding or supplementing
+        user-supplied values from the config files and command line.
+        You'll have to re-finalize the command object (by calling
+        'finalize_options()' or 'ensure_finalized()') before using it for
+        real.
+
+        'command' should be a command name (string) or command object.  If
+        'reinit_subcommands' is true, also reinitializes the command's
+        sub-commands, as declared by the 'sub_commands' class attribute (if
+        it has one).  See the "install_dist" command for an example.  Only
+        reinitializes the sub-commands that actually matter, ie. those
+        whose test predicates return true.
+
+        Returns the reinitialized command object.
+        """
+        from packaging.command.cmd import Command
+        if not isinstance(command, Command):
+            command_name = command
+            command = self.get_command_obj(command_name)
+        else:
+            command_name = command.get_command_name()
+
+        if not command.finalized:
+            return command
+        command.initialize_options()
+        self.have_run[command_name] = 0
+        command.finalized = False
+        self._set_command_options(command)
+
+        if reinit_subcommands:
+            for sub in command.get_sub_commands():
+                self.get_reinitialized_command(sub, reinit_subcommands)
+
+        return command
+
+    # -- Methods that operate on the Distribution ----------------------
+
+    def run_commands(self):
+        """Run each command that was seen on the setup script command line.
+        Uses the list of commands found and cache of command objects
+        created by 'get_command_obj()'.
+        """
+        for cmd in self.commands:
+            self.run_command(cmd)
+
+    # -- Methods that operate on its Commands --------------------------
+
+    def run_command(self, command, options=None):
+        """Do whatever it takes to run a command (including nothing at all,
+        if the command has already been run).  Specifically: if we have
+        already created and run the command named by 'command', return
+        silently without doing anything.  If the command named by 'command'
+        doesn't even have a command object yet, create one.  Then invoke
+        'run()' on that command object (or an existing one).
+        """
+        # Already been here, done that? then return silently.
+        if self.have_run.get(command):
+            return
+
+        if options is not None:
+            self.command_options[command] = options
+
+        cmd_obj = self.get_command_obj(command)
+        cmd_obj.ensure_finalized()
+        self.run_command_hooks(cmd_obj, 'pre_hook')
+        logger.info("running %s", command)
+        cmd_obj.run()
+        self.run_command_hooks(cmd_obj, 'post_hook')
+        self.have_run[command] = 1
+
+    def run_command_hooks(self, cmd_obj, hook_kind):
+        """Run hooks registered for that command and phase.
+
+        *cmd_obj* is a finalized command object; *hook_kind* is either
+        'pre_hook' or 'post_hook'.
+        """
+        if hook_kind not in ('pre_hook', 'post_hook'):
+            raise ValueError('invalid hook kind: %r' % hook_kind)
+
+        hooks = getattr(cmd_obj, hook_kind, None)
+
+        if hooks is None:
+            return
+
+        for hook in hooks.values():
+            if isinstance(hook, str):
+                try:
+                    hook_obj = resolve_name(hook)
+                except ImportError as e:
+                    raise PackagingModuleError(e)
+            else:
+                hook_obj = hook
+
+            if not hasattr(hook_obj, '__call__'):
+                raise PackagingOptionError('hook %r is not callable' % hook)
+
+            logger.info('running %s %s for command %s',
+                        hook_kind, hook, cmd_obj.get_command_name())
+            hook_obj(cmd_obj)
+
+    # -- Distribution query methods ------------------------------------
+    def has_pure_modules(self):
+        return len(self.packages or self.py_modules or []) > 0
+
+    def has_ext_modules(self):
+        return self.ext_modules and len(self.ext_modules) > 0
+
+    def has_c_libraries(self):
+        return self.libraries and len(self.libraries) > 0
+
+    def has_modules(self):
+        return self.has_pure_modules() or self.has_ext_modules()
+
+    def has_headers(self):
+        return self.headers and len(self.headers) > 0
+
+    def has_scripts(self):
+        return self.scripts and len(self.scripts) > 0
+
+    def has_data_files(self):
+        return self.data_files and len(self.data_files) > 0
+
+    def is_pure(self):
+        return (self.has_pure_modules() and
+                not self.has_ext_modules() and
+                not self.has_c_libraries())