check_arg 0.1.3

Usage

Checking optional/positional arguments and auto documenting at the same time

Example by using some currying, the purpose is to achieve auto documentation and validation so that:

>>> @set_default_kw_value(port=1026,nawak=123)
>>> @must_have_key("name")
>>> @min_positional(2)
>>> @validate(name = naming_convention(), port = in_range(1024,1030 ))
>>> def toto(*a,**kw):
...    """useless fonction"""
...    print a
...    print kw
...    print "done"
...        return 1

gives this results:

>>> help(toto)
... Help on function toto in module __main__:
...
... toto(*a, **kw)
...     useless fonction
...
...     **kewords must validate the following rules**:
...
...     * key: <port> must belong to [ 1024, 1030 [,
...     * key: <name> must begin with underscore
...
...     **at_least_n_positional** :2
...
...
...     **keyword_must_contain_key** :name
...
...
...     **default_kw_value** :
...
...     * params: port is 1026,
...     * params: nawak is 123

Use

To create a decorator that will be called before the called functions and which names and arguments will enhance the documentation as in the following example just do:

>>> set_default_kw_value = valid_and_doc(default_kw_value)
>>> min_positional = valid_and_doc(at_least_n_positional)

You can provide a default template for the documention as a second argument::

>>> def in_range(low,high):
...      def _in_range(_int):
...          return high >= _int > low
...      _in_range.__doc__ = """belong to [ %s, %s [""" % (low, high)
...      return _in_range

>>> def _validate(**validator):
...      def wrap(**validator):
...          def rewrapped(*a,**kw):
...              for key,valid in validator.items():
...                  if key in kw and not valid(kw[key]):
...                      raise Exception(
...                          "Key <%s> does not match rule %s" % (
...                              key,default_doc_maker(
...                                  valid,**{ key: kw[key]}
...                      ) ) )
...          return rewrapped
...
>>>      def validate_doc(_validate,  **validator):
...         return """
...
...  **kewords must validate the following rules**:
...
...  %s
...  """ % ( ",\n".join(
...          "* key: <%s> must %s" % (
...                  key, valid.__doc__ is not None and valid.__doc__ or valid.__name__
...                  ) for key, valid in validator.items()
...              ) )
...      return [ wrap, validate_doc ]
...
>>> validate = valid_and_doc(*_validate())

Changelog

• 0.1.0 initial release

• 0.1.(1|2|3) trying to have README.txt being seen as Rst