python setattr 函数

setattr
(
object,
name,
value
)

This is the counterpart of getattr(). The arguments are an object, astring and an arbitrary value. The string may name an existing attribute or anew attribute. The function assigns the value to the attribute, provided theobject allows it. For example, setattr(x, 'foobar', 123) is equivalent tox.foobar = 123.

查阅 python lib reference manual 得到：

yocto bitbake python 脚本中有一段代码用到了这个函数：

class BBConfiguration(object): """ Manages build options and configurations for one run """ def __init__(self, options): for key, val in options.__dict__.items(): setattr(self, key, val) self.pkgs_to_build = [] 

def main(): parser = optparse.OptionParser( version = "BitBake Build Tool Core version %s, %%prog version %s" % (bb.__version__, __version__), usage = """%prog [options] [package ...] Executes the specified task (default is 'build') for a given set of BitBake files. It expects that BBFILES is defined, which is a space separated list of files to be executed. BBFILES does support wildcards. Default BBFILES are the .bb files in the current directory.""") parser.add_option("-b", "--buildfile", help = "execute the task against this .bb file, rather than a package from BBFILES. Does not handle any dependencies.", action = "store", dest = "buildfile", default = None) parser.add_option("-k", "--continue", help = "continue as much as possible after an error. While the target that failed, and those that depend on it, cannot be remade, the other dependencies of these targets can be processed all the same.", action = "store_false", dest = "abort", default = True) parser.add_option("-a", "--tryaltconfigs", help = "continue with builds by trying to use alternative providers where possible.", action = "store_true", dest = "tryaltconfigs", default = False) parser.add_option("-f", "--force", help = "force run of specified cmd, regardless of stamp status", action = "store_true", dest = "force", default = False) parser.add_option("-c", "--cmd", help = "Specify task to execute. Note that this only executes the specified task for the providee and the packages it depends on, i.e. 'compile' does not implicitly call stage for the dependencies (IOW: use only if you know what you are doing). Depending on the base.bbclass a listtasks tasks is defined and will show available tasks", action = "store", dest = "cmd") parser.add_option("-C", "--clear-stamp", help = "Invalidate the stamp for the specified cmd such as 'compile' and run the default task for the specified target(s)", action = "store", dest = "invalidate_stamp") parser.add_option("-r", "--read", help = "read the specified file before bitbake.conf", action = "append", dest = "prefile", default = []) parser.add_option("-R", "--postread", help = "read the specified file after bitbake.conf", action = "append", dest = "postfile", default = []) parser.add_option("-v", "--verbose", help = "output more chit-chat to the terminal", action = "store_true", dest = "verbose", default = False) parser.add_option("-D", "--debug", help = "Increase the debug level. You can specify this more than once.", action = "count", dest="debug", default = 0) parser.add_option("-n", "--dry-run", help = "don't execute, just go through the motions", action = "store_true", dest = "dry_run", default = False) parser.add_option("-S", "--dump-signatures", help = "don't execute, just dump out the signature construction information", action = "store_true", dest = "dump_signatures", default = False) parser.add_option("-p", "--parse-only", help = "quit after parsing the BB files (developers only)", action = "store_true", dest = "parse_only", default = False) parser.add_option("-s", "--show-versions", help = "show current and preferred versions of all recipes", action = "store_true", dest = "show_versions", default = False) parser.add_option("-e", "--environment", help = "show the global or per-package environment (this is what used to be bbread)", action = "store_true", dest = "show_environment", default = False) parser.add_option("-g", "--graphviz", help = "emit the dependency trees of the specified packages in the dot syntax, and the pn-buildlist to show the build list", action = "store_true", dest = "dot_graph", default = False) parser.add_option("-I", "--ignore-deps", help = """Assume these dependencies don't exist and are already provided (equivalent to ASSUME_PROVIDED). Useful to make dependency graphs more appealing""", action = "append", dest = "extra_assume_provided", default = []) parser.add_option("-l", "--log-domains", help = """Show debug logging for the specified logging domains""", action = "append", dest = "debug_domains", default = []) parser.add_option("-P", "--profile", help = "profile the command and print a report", action = "store_true", dest = "profile", default = False) parser.add_option("-u", "--ui", help = "userinterface to use", action = "store", dest = "ui") parser.add_option("-t", "--servertype", help = "Choose which server to use, none, process or xmlrpc", action = "store", dest = "servertype") parser.add_option("", "--revisions-changed", help = "Set the exit code depending on whether upstream floating revisions have changed or not", action = "store_true", dest = "revisions_changed", default = False) parser.add_option("", "--server-only", help = "Run bitbake without UI, the frontend can connect with bitbake server itself", action = "store_true", dest = "server_only", default = False) parser.add_option("-B", "--bind", help = "The name/address for the bitbake server to bind to", action = "store", dest = "bind", default = False) parser.add_option("", "--no-setscene", help = "Do not run any setscene tasks, forces builds", action = "store_true", dest = "nosetscene", default = False) options, args = parser.parse_args(sys.argv) configuration = BBConfiguration(options) configuration.pkgs_to_build.extend(args[1:])

其中：