OptDict

Python module for easy to use command line options. With validation options values and configuration from JSON file.

Example

Example usage for command line params

from optdict import Parser, validators

options_dict = {
    # Params section "main"
    "main": {
        "listen": {
            # Command line keys (require)
            "keys": ["-l", "--listen"],

            # Validator call for value (optional)
            "validator": validators.Valid(lambda addr: ".".join([str(j) for j in [int(i) for i in addr.split(".")] if j >=0 and j<256]) == addr),

            # Help text (optional)
            "help": "Listen address",

            # Default value (optional default None)
            "default": "127.0.0.1",

            # Action (optional)
            # support all OptParse options
            # * store_true - stores true (default False)
            # * store_false - stores false (default True)
            # * store_const - stores constans
            # * count - stores the number of repetitions of the key (if only key is single symbol)
            # * callback - run function defined to "callback" option (see OptParse docs)
            "action": "store_const"
        },
        "test": {
            "keys": ["-t"],
            "help": "Test someone",
            "action": "callback",
            "callback": lambda x: exit(0),
        }
    },
    # Another section
    "debug": {
        "debug": {
            "keys": ['-d'],
            "action": "count",
            "default": 0,
            "type": "int",
            "help": "Debuging output"
        },
        "__meta__": {
            "help": "Main section",
            "text": "Alternative syntax"
        }
    },
    # Meta section
    "__meta__": {
        # Help messages for sections
        "sections_help": {
            "debug": "Debugging options",
        },
        "sections_text": {
            "Debug": "This section contains debug options for test this..."
        }
    }
}

if __name__ == "__main__":
    options, args = Parser(options_dict).parse_args()

    print "Listen:", options.main_listen
    print "Debug:", options.debug_debug

And run it:

$ python test.py --help
Usage: test.py [options]

Options:
  -h, --help            show this help message and exit
  --config=FILE         Set options from JSON file (generate example by --gen-conf).
  --gen-conf            Print sample config file and exit.

  Debugging options:
    -d                  Debuging output

  Main options:
    This section contains main options for test this...

    -t                  Test someone
    -l MAIN_LISTEN, --listen=MAIN_LISTEN
                        Listen address

Validations

The module provides this validators:

• RequireAll(func1[, func2, ... funcN]) {synonym: Require}
• RequireOnce(func1[, func2, ... funcN])
• ValidAll(name1[, name2 ... nameN]) {synonym: Valid}
• ValidOnce(name1[, name2 ... nameN])
• Conflict(name1[, name2 ... nameN])
• ValidationQueue(Validator0[, Validator1])
• Modifier(func1[, func2 ... funcN)

Call example:

options_dict = {
    # Params section "main"
    "main": {
        "listen_address": {
            "keys": ["-l", "--listen"],
            "validator": validators.ValidOnce(
                lambda addr: ".".join([str(j) for j in [int(i) for i in addr.split(".")] if j >=0 and j<256]) == addr,
                lambda path: os.path.exists(os.path.basedir(path),
            )
            "help": "Listen address",
        },
        "port": {
            "keys": ["-p", "--port"],
            # if "unix_socket" option defined, call exception
            # key critical - if true then exit(128)
            "validator": Conflict("unix_socket", critical=True)
        },
        "unix_socket": {
            "keys": ["--socket"],
            "help": "Force listen unix socket"
        }
    }
}

RequireAll

arguments: (*names) synonym: Require

Test if all options from args is set

example:

RequireAll("main_listen", "main_port")

RequireOnce

arguments: (*names)

Test if once option from args is set

example (for optopn test from main section (main_test)):

RequireOnce("main_listen", "main_port", "main_socket")

Conflict

arguments: (*names)

Test if other options not set (and bool(default) == False)

example (for option name "main_listen"):

Conflict("main_test") # Exception if option test from main section is set

ValidAll

arguments: (*funcs, critical=True) synonym: Valid

If at least one function returns false, an exception is thrown.

example:

Valid(
    lambda x: x >= 0,
    lambda x: x < 256
)

ValidOnce

arguments: (*funcs, critical=True)

If at least one function returns true, an exception is thrown.

example:

ValidOnce(
    lambda x: x >= 0 and x < 256,
    lambda x: x == -1
)

ValidationQueue

Validate Multiple validators

example:

ValidateQueue(
    ValidAll(
        lambda x: x >= 0,
        lambda x: x != -1,
    ),
    ValidOnce(
        lambda x: x < 0,
        lambda x: x > 10,
    )
)

Modifier

Modify value

example:

Modifier(
    lambda f: open(f).read()
)

Configuration from JSON file

OptDict added options "--config" and "--gen-conf" in root section.

Generate example configuration

To create a configuration example, a call option "generate". Configuration will be printed.

Read configuration from file

Create a sample configuration as follows:

# python test.py --gen-conf | tee /tmp/sample.json
{
 "debug": {
  "debug": 0
 },
 "main": {
  "test": null,
  "listen": "127.0.0.1"
 }
}

Edit /tmp/sample.json:

{
 "debug": {
  "debug": 999
 },
 "main": {
  "test": null,
  "listen": "0.0.0.0"
 }
}

Run test with config file:

$ python test.py --config /tmp/sample.json
Listen: 0.0.0.0
Debug: 999

Start options override the config file:

$ python readme.py --config /tmp/sample.json -l 10.0.0.1
Listen: 10.0.0.1
Debug: 999

Options usage

Example usage for optdict after parse options

if __name__ == "__main__":
    options, args = Parser(options_dict).parse_args()

    print "Listen:", options.main_listen
    print "Debug:", options.debug_debug

Attribute naming

The naming attribute is the next rule:

section_optionname

thus, the option "listen" in the section "main" is an attribute of "main_listen"

Current config (dictionary)

Method options.to_dict() returns dictionary of dictionaries of values