Skip to main content

traitscli - CLI generator based on class traits

Project description

Traits CLI is based on Enthought’s Traits library.

Some benefits:

  • Automatically set type (int/float/…) of command line argument.

  • Help string generation.

  • “Deep value”” configuration: e.g., --dict['a']['b']['c']=1 is equivalent to obj.dict['a']['b']['c'] = 1 in Python code.

  • Nested class configuration: e.g., --sub.attr=val is equivalent to obj.sub.attr = val in Python code.

  • Parameter file support (ini/conf, json, yaml, etc.). Load parameter from file then set attribute.


pip install traitscli


  • traits

  • argparse (for Python < 2.7)


Source code:

from traitscli import TraitsCLIBase
from traits.api import Bool, Float, Int, Str, Enum

class SampleCLI(TraitsCLIBase):

    Sample CLI using `traitscli`.


      %(prog)s --yes                # => obj.yes = True
      %(prog)s --string something   # => obj.string = 'string'
      %(prog)s --choice x           # => raise error (x is not in {a, b, c})


    # These variables are configurable by command line option
    yes = Bool(desc='yes flag for sample CLI', config=True)
    no = Bool(True, config=True)
    fnum = Float(config=True)
    inum = Int(config=True)
    string = Str(config=True)
    choice = Enum(['a', 'b', 'c'], config=True)

    # You can have "internal" attributes which cannot be set via CLI.
    not_configurable_from_cli = Bool()

    def do_run(self):
        names = self.class_trait_names(config=True)
        width = max(map(len, names))
        for na in names:
            print "{0:{1}} : {2!r}".format(na, width, getattr(self, na))

if __name__ == '__main__':
    # Run command line interface

Example run:

$ python --help
usage: [-h] [--choice {a,b,c}] [--fnum FNUM] [--inum INUM] [--no]
                 [--string STRING] [--yes]

Sample CLI using `traitscli`.

Example:: --yes                # => obj.yes = True --string something   # => obj.string = 'string' --choice x           # => raise error (x is not in {a, b, c})

optional arguments:
  -h, --help        show this help message and exit
  --choice {a,b,c}  (default: a)
  --fnum FNUM       (default: 0.0)
  --inum INUM       (default: 0)
  --no              (default: True)
  --string STRING   (default: )
  --yes             yes flag for sample CLI (default: False)

$ python --yes --choice a
string : ''
no     : True
fnum   : 0.0
choice : 'a'
inum   : 0
yes    : True

$ python --inum invalid_argument
usage: [-h] [--choice {a,b,c}] [--fnum FNUM] [--inum INUM] [--no]
                 [--string STRING] [--yes] error: argument --inum: invalid int value: 'invalid_argument'

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

traitscli-0.1.0.tar.gz (10.9 kB view hashes)

Uploaded source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page