![]() That's a problem I find with most popular argument parsing options is that if your parameters are only modest, the code to document them becomes disproportionately large to the benefit they provide.Ī relative new-comer to the argument parsing scene (I think) is plac. You then usually want to loop on this list and test the option name as in the example.Īrgparse code can be longer than actual implementation code! If an option doesn't accept any argument (like -help here) the arg part is an empty string. The result is a list of couple (option,argument) The = after output once again means that output accepts one arguments. The : means that -o accepts one argument.įinally describes long arguments ( -MORETHANONELETTER ). "ho:v" here describes the short arguments : -ONELETTER. Getopt.getopt will parse it according to the rule you give in argument. Like in C you skip the first element which is the name of your program and parse only the arguments : sys.argv Sys.argv is pretty much your char** argv in C. Those who are receiving arguments, and those who are Opts, args = getopt.getopt(sys.argv, "ho:v", ) Here is the example code for the doc : import getopt, sys Here's a simple example from the documentation (this small program exposes the function double to the command line): import fireįrom the command line, you can run: > calculator.py double 10 It can generate a CLI interface for your code with you doing zero argument parsing. Since 2017 there's another cool module called python-fire. So this is it: 2 lines of code plus your doc string which is essential and you get your arguments parsed and available in your arguments object. Naval_fate.py mine (set|remove) Īrguments = docopt(_doc_, version='Naval Fate 2.0') Here is an example taken from its documentation: """Naval Fate. Since 2012 there is a very easy, powerful and really cool module for argument parsing called docopt. It's not something I can easily explain in a few lines, but feel free to browse around in my repository for the main class, as well as a class that uses it and the option parser It uses optparse heavily to chain commands together. In one of my projects, I created a Command class which allows you to nest subcommands in a command tree easily. Save it in sample.py, and run it once with python sample.pyĪnd once with python sample.py -query myqueryīeyond that, you will find that optparse is very easy to extend. Here's a complete Python script that shows this: import optparseĥ lines of python that show you the basics. You create a parser simply by doing parser = optparse.OptionParser() Options.query will then be set to the value you passed to the script. This will, by default, parse the standard arguments passed to the script (sys.argv) Usually you parse your arguments with: options, args = parser.parse_args() It is also self-documenting in that you declare the help argument (which will be used when run with -h/-help) right there with the option. It pretty much speaks for itself at processing time, it will accept -q or -query as options, store the argument in an attribute called query and has a default value if you don't specify it. Here's a typical line to add an option to your parser: parser.add_option('-q', '-query', Optparse, while being a bit more verbose, is much better structured and simpler to extend later on. getopt is pretty much a one-to-one mapping of the standard getopt(3) C library functions, and not very easy to use. ![]() See this answer for more information.Īs other people pointed out, you are better off going with optparse over getopt. For Python 2.7 and above, argparse replaces optparse. This answer suggests optparse which is appropriate for older Python versions. ![]() opt_arg OPT_ARG An optional integer argument h, -help show this help message and exit Opt_pos_arg An optional integer positional argument Pos_arg A required integer positional argument Usage: app pos_arg Ĭonvert: error: pos_arg cannot be larger than 10 Usage: convert pos_arg Īpp: error: argument pos_arg: invalid int value: 'foo' Parser.error("pos_arg cannot be larger than 10")Ĭorrect use: $. Parser.add_argument('-switch', action='store_true', ![]() Parser.add_argument('-opt_arg', type=int, ![]() Help='An optional integer positional argument') Parser.add_argument('opt_pos_arg', type=int, nargs='?', Help='A required integer positional argument') Parser = argparse.ArgumentParser(description='Optional app description')Ģ) Add Arguments # Required positional argument Here is a short summary of how to use it: ![]()
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