Example #1
0
    def __init__(self, cmd, *args, **kargs):
        if isinstance(cmd, unicode):
            self.name = str(cmd)
        elif isinstance(cmd, str):
            self.name = cmd
        else:
            raise GrassError("Problem initializing the module {s}".format(s=cmd))
        try:
            # call the command with --interface-description
            get_cmd_xml = Popen([cmd, "--interface-description"], stdout=PIPE)
        except OSError as e:
            print("OSError error({0}): {1}".format(e.errno, e.strerror))
            str_err = "Error running: `%s --interface-description`."
            raise GrassError(str_err % self.name)
        # get the xml of the module
        self.xml = get_cmd_xml.communicate()[0]
        # transform and parse the xml into an Element class:
        # http://docs.python.org/library/xml.etree.elementtree.html
        tree = fromstring(self.xml)

        for e in tree:
            if e.tag not in ('parameter', 'flag'):
                self.__setattr__(e.tag, GETFROMTAG[e.tag](e))

        #
        # extract parameters from the xml
        #
        self.params_list = [Parameter(p) for p in tree.findall("parameter")]
        self.inputs = TypeDict(Parameter)
        self.outputs = TypeDict(Parameter)
        self.required = []

        # Insert parameters into input/output and required
        for par in self.params_list:
            if par.input:
                self.inputs[par.name] = par
            else:
                self.outputs[par.name] = par
            if par.required:
                self.required.append(par.name)

        #
        # extract flags from the xml
        #
        flags_list = [Flag(f) for f in tree.findall("flag")]
        self.flags = TypeDict(Flag)
        for flag in flags_list:
            self.flags[flag.name] = flag

        #
        # Add new attributes to the class
        #
        self.run_ = True
        self.finish_ = True
        self.env_ = None
        self.stdin_ = None
        self.stdin = None
        self.stdout_ = None
        self.stderr_ = None
        diz = {'name': 'stdin', 'required': False,
               'multiple': False, 'type': 'all',
               'value': None}
        self.inputs['stdin'] = Parameter(diz=diz)
        diz['name'] = 'stdout'
        self.outputs['stdout'] = Parameter(diz=diz)
        diz['name'] = 'stderr'
        self.outputs['stderr'] = Parameter(diz=diz)
        self.popen = None
        self.time = None

        if args or kargs:
            self.__call__(*args, **kargs)
        self.__call__.__func__.__doc__ = self.__doc__
Example #2
0
    def __init__(self, cmd, *args, **kargs):
        if isinstance(cmd, unicode):
            self.name = str(cmd)
        elif isinstance(cmd, str):
            self.name = cmd
        else:
            raise GrassError(
                "Problem initializing the module {s}".format(s=cmd))
        try:
            # call the command with --interface-description
            get_cmd_xml = Popen([cmd, "--interface-description"], stdout=PIPE)
        except OSError as e:
            print("OSError error({0}): {1}".format(e.errno, e.strerror))
            str_err = "Error running: `%s --interface-description`."
            raise GrassError(str_err % self.name)
        # get the xml of the module
        self.xml = get_cmd_xml.communicate()[0]
        # transform and parse the xml into an Element class:
        # http://docs.python.org/library/xml.etree.elementtree.html
        tree = fromstring(self.xml)

        for e in tree:
            if e.tag not in ('parameter', 'flag'):
                self.__setattr__(e.tag, GETFROMTAG[e.tag](e))

        #
        # extract parameters from the xml
        #
        self.params_list = [Parameter(p) for p in tree.findall("parameter")]
        self.inputs = TypeDict(Parameter)
        self.outputs = TypeDict(Parameter)
        self.required = []

        # Insert parameters into input/output and required
        for par in self.params_list:
            if par.input:
                self.inputs[par.name] = par
            else:
                self.outputs[par.name] = par
            if par.required:
                self.required.append(par.name)

        #
        # extract flags from the xml
        #
        flags_list = [Flag(f) for f in tree.findall("flag")]
        self.flags = TypeDict(Flag)
        for flag in flags_list:
            self.flags[flag.name] = flag

        #
        # Add new attributes to the class
        #
        self.run_ = True
        self.finish_ = True
        self.env_ = None
        self.stdin_ = None
        self.stdin = None
        self.stdout_ = None
        self.stderr_ = None
        diz = {
            'name': 'stdin',
            'required': False,
            'multiple': False,
            'type': 'all',
            'value': None
        }
        self.inputs['stdin'] = Parameter(diz=diz)
        diz['name'] = 'stdout'
        self.outputs['stdout'] = Parameter(diz=diz)
        diz['name'] = 'stderr'
        self.outputs['stderr'] = Parameter(diz=diz)
        self.popen = None
        self.time = None

        if args or kargs:
            self.__call__(*args, **kargs)
        self.__call__.__func__.__doc__ = self.__doc__
Example #3
0
class Module(object):
    """This class is design to wrap/run/interact with the GRASS modules.

    The class during the init phase read the XML description generate using
    the ``--interface-description`` in order to understand which parameters
    are required which optionals. ::

    >>> from grass.pygrass.modules import Module
    >>> from subprocess import PIPE
    >>> import copy

    >>> region = Module("g.region")
    >>> region.flags.p = True  # set flags
    >>> region.flags.u = True
    >>> region.flags["3"].value = True  # set numeric flags
    >>> region.get_bash()
    u'g.region -p -3 -u'
    >>> new_region = copy.deepcopy(region)
    >>> new_region.inputs.res = "10"
    >>> new_region.get_bash()
    u'g.region res=10 -p -3 -u'

    >>> neighbors = Module("r.neighbors")
    >>> neighbors.inputs.input = "mapA"
    >>> neighbors.outputs.output = "mapB"
    >>> neighbors.inputs.size = 5
    >>> neighbors.inputs.quantile = 0.5
    >>> neighbors.get_bash()
    u'r.neighbors input=mapA method=average size=5 quantile=0.5 output=mapB'

    >>> new_neighbors1 = copy.deepcopy(neighbors)
    >>> new_neighbors1.inputs.input = "mapD"
    >>> new_neighbors1.inputs.size = 3
    >>> new_neighbors1.inputs.quantile = 0.5
    >>> new_neighbors1.get_bash()
    u'r.neighbors input=mapD method=average size=3 quantile=0.5 output=mapB'

    >>> new_neighbors2 = copy.deepcopy(neighbors)
    >>> new_neighbors2(input="mapD", size=3, run_=False)
    Module('r.neighbors')
    >>> new_neighbors2.get_bash()
    u'r.neighbors input=mapD method=average size=3 quantile=0.5 output=mapB'

    >>> neighbors = Module("r.neighbors")
    >>> neighbors.get_bash()
    u'r.neighbors method=average size=3'

    >>> new_neighbors3 = copy.deepcopy(neighbors)
    >>> new_neighbors3(input="mapA", size=3, output="mapB", run_=False)
    Module('r.neighbors')
    >>> new_neighbors3.get_bash()
    u'r.neighbors input=mapA method=average size=3 output=mapB'

    >>> mapcalc = Module("r.mapcalc", expression="test_a = 1",
    ...                  overwrite=True, run_=False)
    >>> mapcalc.run()
    Module('r.mapcalc')
    >>> mapcalc.popen.returncode
    0

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, stdout_=PIPE,
    ...                 stderr_=PIPE, stdin_="1 red")
    >>> colors.run()
    Module('r.colors')
    >>> colors.popen.returncode
    0
    >>> colors.inputs["stdin"].value
    u'1 red'
    >>> colors.outputs["stdout"].value
    u''
    >>> colors.outputs["stderr"].value.strip()
    "Color table for raster map <test_a> set to 'rules'"

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, finish_=False, stdin_=PIPE)
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 red")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, finish_=False,
    ...                 stdin_=PIPE, stderr_=PIPE)
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 red")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr.strip()
    "Color table for raster map <test_a> set to 'rules'"

    Run a second time
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 blue")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr.strip()
    "Color table for raster map <test_a> set to 'rules'"

    Multiple run test
    >>> colors = Module("r.colors", map="test_a",
    ...                                            color="ryb", run_=False)
    >>> colors.run()
    Module('r.colors')
    >>> colors(color="gyr")
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> colors(color="ryg")
    Module('r.colors')
    >>> colors(stderr_=PIPE)
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> print(colors.outputs["stderr"].value.strip())
    Color table for raster map <test_a> set to 'ryg'
    >>> colors(color="byg")
    Module('r.colors')
    >>> colors(stdout_=PIPE)
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> print(colors.outputs["stderr"].value.strip())
    Color table for raster map <test_a> set to 'byg'

    Often in the Module class you can find ``*args`` and ``kwargs`` annotation
    in methods, like in the __call__ method.
    Python allow developers to not specify all the arguments and
    keyword arguments of a method or function. ::

        def f(*args):
            for arg in args:
                print arg

    therefore if we call the function like:

    >>> f('grass', 'gis', 'modules')                     # doctest: +SKIP
    grass
    gis
    modules

    or we can define a new list:

    >>> words = ['grass', 'gis', 'modules']              # doctest: +SKIP
    >>> f(*words)                                        # doctest: +SKIP
    grass
    gis
    modules

    we can do the same with keyword arguments, rewrite the above function: ::

        def f(*args, **kargs):
            for arg in args:
                print arg
            for key, value in kargs.items():
                print "%s = %r" % (key, value)

    now we can use the new function, with:

    >>> f('grass', 'gis', 'modules', os = 'linux', language = 'python')
    ...                                                  # doctest: +SKIP
    grass
    gis
    modules
    os = 'linux'
    language = 'python'

    or, as before we can, define a dictionary and give the dictionary to
    the function, like:

    >>> keywords = {'os' : 'linux', 'language' : 'python'}  # doctest: +SKIP
    >>> f(*words, **keywords)                            # doctest: +SKIP
    grass
    gis
    modules
    os = 'linux'
    language = 'python'

    In the Module class we heavily use this language feature to pass arguments
    and keyword arguments to the grass module.
    """
    def __init__(self, cmd, *args, **kargs):
        if isinstance(cmd, unicode):
            self.name = str(cmd)
        elif isinstance(cmd, str):
            self.name = cmd
        else:
            raise GrassError("Problem initializing the module {s}".format(s=cmd))
        try:
            # call the command with --interface-description
            get_cmd_xml = Popen([cmd, "--interface-description"], stdout=PIPE)
        except OSError as e:
            print("OSError error({0}): {1}".format(e.errno, e.strerror))
            str_err = "Error running: `%s --interface-description`."
            raise GrassError(str_err % self.name)
        # get the xml of the module
        self.xml = get_cmd_xml.communicate()[0]
        # transform and parse the xml into an Element class:
        # http://docs.python.org/library/xml.etree.elementtree.html
        tree = fromstring(self.xml)

        for e in tree:
            if e.tag not in ('parameter', 'flag'):
                self.__setattr__(e.tag, GETFROMTAG[e.tag](e))

        #
        # extract parameters from the xml
        #
        self.params_list = [Parameter(p) for p in tree.findall("parameter")]
        self.inputs = TypeDict(Parameter)
        self.outputs = TypeDict(Parameter)
        self.required = []

        # Insert parameters into input/output and required
        for par in self.params_list:
            if par.input:
                self.inputs[par.name] = par
            else:
                self.outputs[par.name] = par
            if par.required:
                self.required.append(par.name)

        #
        # extract flags from the xml
        #
        flags_list = [Flag(f) for f in tree.findall("flag")]
        self.flags = TypeDict(Flag)
        for flag in flags_list:
            self.flags[flag.name] = flag

        #
        # Add new attributes to the class
        #
        self.run_ = True
        self.finish_ = True
        self.env_ = None
        self.stdin_ = None
        self.stdin = None
        self.stdout_ = None
        self.stderr_ = None
        diz = {'name': 'stdin', 'required': False,
               'multiple': False, 'type': 'all',
               'value': None}
        self.inputs['stdin'] = Parameter(diz=diz)
        diz['name'] = 'stdout'
        self.outputs['stdout'] = Parameter(diz=diz)
        diz['name'] = 'stderr'
        self.outputs['stderr'] = Parameter(diz=diz)
        self.popen = None
        self.time = None

        if args or kargs:
            self.__call__(*args, **kargs)
        self.__call__.__func__.__doc__ = self.__doc__

    def __call__(self, *args, **kargs):
        """Set module paramters to the class and, if run_ is True execute the
        module, therefore valid parameters are all the module parameters
        plus some extra parameters that are: run_, stdin_, stdout_, stderr_,
        env_ and finish_.
        """
        if not args and not kargs:
            self.run()
            return self

        #
        # check for extra kargs, set attribute and remove from dictionary
        #
        if 'flags' in kargs:
            for flg in kargs['flags']:
                self.flags[flg].value = True
            del(kargs['flags'])

        # set attributs
        for key in ('run_', 'env_', 'finish_', 'stdout_', 'stderr_'):
            if key in kargs:
                setattr(self, key, kargs.pop(key))

        # set inputs
        for key in ('stdin_', ):
            if key in kargs:
                self.inputs[key[:-1]].value = kargs.pop(key)

        #
        # check args
        #
        for param, arg in zip(self.params_list, args):
            param.value = arg
        for key, val in kargs.items():
            if key in self.inputs:
                self.inputs[key].value = val
            elif key in self.outputs:
                self.outputs[key].value = val
            elif key in self.flags:
                # we need to add this, because some parameters (overwrite,
                # verbose and quiet) work like parameters
                self.flags[key].value = val
            else:
                raise ParameterError('%s is not a valid parameter.' % key)

        #
        # check if execute
        #
        if self.run_:
            #
            # check reqire parameters
            #
            for k in self.required:
                if ((k in self.inputs and self.inputs[k].value is None) or
                        (k in self.outputs and self.outputs[k].value is None)):
                    msg = "Required parameter <%s> not set."
                    raise ParameterError(msg % k)
            return self.run()
        return self

    def get_bash(self):
        """Return a BASH rapresentation of the Module."""
        return ' '.join(self.make_cmd())

    def get_python(self):
        """Return a Python rapresentation of the Module."""
        prefix = self.name.split('.')[0]
        name = '_'.join(self.name.split('.')[1:])
        params = ', '.join([par.get_python() for par in self.params_list
                           if par.get_python() != ''])
        flags = ''.join([flg.get_python()
                         for flg in self.flags.values()
                         if not flg.special and flg.get_python() != ''])
        special = ', '.join([flg.get_python()
                             for flg in self.flags.values()
                             if flg.special and flg.get_python() != ''])
        #     pre name par flg special
        if flags and special:
            return "%s.%s(%s, flags=%r, %s)" % (prefix, name, params,
                                                flags, special)
        elif flags:
            return "%s.%s(%s, flags=%r)" % (prefix, name, params, flags)
        elif special:
            return "%s.%s(%s, %s)" % (prefix, name, params, special)
        else:
            return "%s.%s(%s)" % (prefix, name, params)

    def __str__(self):
        """Return the command string that can be executed in a shell"""
        return ' '.join(self.make_cmd())

    def __repr__(self):
        return "Module(%r)" % self.name

    @docstring_property(__doc__)
    def __doc__(self):
        """{cmd_name}({cmd_params})
        """
        head = DOC['head'].format(cmd_name=self.name,
            cmd_params=('\n' +  # go to a new line
             # give space under the function name
             (' ' * (len(self.name) + 1))).join([', '.join(
             # transform each parameter in string
             [str(param) for param in line if param is not None])
             # make a list of parameters with only 3 param per line
             for line in zip_longest(*[iter(self.params_list)] * 3)]),)
        params = '\n'.join([par.__doc__ for par in self.params_list])
        flags = self.flags.__doc__
        return '\n'.join([head, params, DOC['flag_head'], flags, DOC['foot']])

    def get_dict(self):
        """Return a dictionary that includes the name, all valid
        inputs, outputs and flags
        """
        dic = {}
        dic['name'] = self.name
        dic['inputs'] = [(k, v.value) for k, v in self.inputs.items()
                         if v.value]
        dic['outputs'] = [(k, v.value) for k, v in self.outputs.items()
                          if v.value]
        dic['flags'] = [flg for flg in self.flags if self.flags[flg].value]
        return dic

    def make_cmd(self):
        """Create the command string that can be executed in a shell

        :returns: the command string
        """
        skip = ['stdin', 'stdout', 'stderr']
        args = [self.name, ]
        for key in self.inputs:
            if key not in skip and self.inputs[key].value:
                args.append(self.inputs[key].get_bash())
        for key in self.outputs:
            if key not in skip and self.outputs[key].value:
                args.append(self.outputs[key].get_bash())
        for flg in self.flags:
            if self.flags[flg].value:
                args.append(str(self.flags[flg]))
        return args

    @mdebug(1, extra=_get_bash)
    def run(self):
        """Run the module

        :param node:
        :type node:

        This function will wait for the process to terminate in case
        finish_==True and sets up stdout and stderr. If finish_==False this
        function will return after starting the process. Use
        self.popen.communicate() of self.popen.wait() to wait for the process
        termination. The handling of stdout and stderr must then be done
        outside of this function.
        """
        if self.inputs['stdin'].value:
            self.stdin = self.inputs['stdin'].value
            self.stdin_ = PIPE

        cmd = self.make_cmd()
        start = time.time()
        self.popen = Popen(cmd,
                           stdin=self.stdin_,
                           stdout=self.stdout_,
                           stderr=self.stderr_,
                           env=self.env_)
        if self.finish_:
            stdout, stderr = self.popen.communicate(input=self.stdin)
            self.outputs['stdout'].value = stdout if stdout else ''
            self.outputs['stderr'].value = stderr if stderr else ''
            self.time = time.time() - start
            if self.popen.poll():
                raise CalledModuleError(returncode=self.popen.returncode,
                                        code=self.get_bash(),
                                        module=self.name, errors=stderr)
        return self
Example #4
0
class Module(object):
    """This class is design to wrap/run/interact with the GRASS modules.

    The class during the init phase read the XML description generate using
    the ``--interface-description`` in order to understand which parameters
    are required which optionals. ::

    >>> from grass.pygrass.modules import Module
    >>> from subprocess import PIPE
    >>> import copy

    >>> region = Module("g.region")
    >>> region.flags.p = True  # set flags
    >>> region.flags.u = True
    >>> region.flags["3"].value = True  # set numeric flags
    >>> region.get_bash()
    u'g.region -p -3 -u'
    >>> new_region = copy.deepcopy(region)
    >>> new_region.inputs.res = "10"
    >>> new_region.get_bash()
    u'g.region res=10 -p -3 -u'

    >>> neighbors = Module("r.neighbors")
    >>> neighbors.inputs.input = "mapA"
    >>> neighbors.outputs.output = "mapB"
    >>> neighbors.inputs.size = 5
    >>> neighbors.inputs.quantile = 0.5
    >>> neighbors.get_bash()
    u'r.neighbors input=mapA method=average size=5 quantile=0.5 output=mapB'

    >>> new_neighbors1 = copy.deepcopy(neighbors)
    >>> new_neighbors1.inputs.input = "mapD"
    >>> new_neighbors1.inputs.size = 3
    >>> new_neighbors1.inputs.quantile = 0.5
    >>> new_neighbors1.get_bash()
    u'r.neighbors input=mapD method=average size=3 quantile=0.5 output=mapB'

    >>> new_neighbors2 = copy.deepcopy(neighbors)
    >>> new_neighbors2(input="mapD", size=3, run_=False)
    Module('r.neighbors')
    >>> new_neighbors2.get_bash()
    u'r.neighbors input=mapD method=average size=3 quantile=0.5 output=mapB'

    >>> neighbors = Module("r.neighbors")
    >>> neighbors.get_bash()
    u'r.neighbors method=average size=3'

    >>> new_neighbors3 = copy.deepcopy(neighbors)
    >>> new_neighbors3(input="mapA", size=3, output="mapB", run_=False)
    Module('r.neighbors')
    >>> new_neighbors3.get_bash()
    u'r.neighbors input=mapA method=average size=3 output=mapB'

    >>> mapcalc = Module("r.mapcalc", expression="test_a = 1",
    ...                  overwrite=True, run_=False)
    >>> mapcalc.run()
    Module('r.mapcalc')
    >>> mapcalc.popen.returncode
    0

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, stdout_=PIPE,
    ...                 stderr_=PIPE, stdin_="1 red")
    >>> colors.run()
    Module('r.colors')
    >>> colors.popen.returncode
    0
    >>> colors.inputs["stdin"].value
    u'1 red'
    >>> colors.outputs["stdout"].value
    u''
    >>> colors.outputs["stderr"].value.strip()
    "Color table for raster map <test_a> set to 'rules'"

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, finish_=False, stdin_=PIPE)
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 red")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr

    >>> colors = Module("r.colors", map="test_a", rules="-",
    ...                 run_=False, finish_=False,
    ...                 stdin_=PIPE, stderr_=PIPE)
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 red")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr.strip()
    "Color table for raster map <test_a> set to 'rules'"

    Run a second time
    >>> colors.run()
    Module('r.colors')
    >>> stdout, stderr = colors.popen.communicate(input="1 blue")
    >>> colors.popen.returncode
    0
    >>> stdout
    >>> stderr.strip()
    "Color table for raster map <test_a> set to 'rules'"

    Multiple run test
    >>> colors = Module("r.colors", map="test_a",
    ...                                            color="ryb", run_=False)
    >>> colors.run()
    Module('r.colors')
    >>> colors(color="gyr")
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> colors(color="ryg")
    Module('r.colors')
    >>> colors(stderr_=PIPE)
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> print(colors.outputs["stderr"].value.strip())
    Color table for raster map <test_a> set to 'ryg'
    >>> colors(color="byg")
    Module('r.colors')
    >>> colors(stdout_=PIPE)
    Module('r.colors')
    >>> colors.run()
    Module('r.colors')
    >>> print(colors.outputs["stderr"].value.strip())
    Color table for raster map <test_a> set to 'byg'

    Often in the Module class you can find ``*args`` and ``kwargs`` annotation
    in methods, like in the __call__ method.
    Python allow developers to not specify all the arguments and
    keyword arguments of a method or function. ::

        def f(*args):
            for arg in args:
                print arg

    therefore if we call the function like:

    >>> f('grass', 'gis', 'modules')                     # doctest: +SKIP
    grass
    gis
    modules

    or we can define a new list:

    >>> words = ['grass', 'gis', 'modules']              # doctest: +SKIP
    >>> f(*words)                                        # doctest: +SKIP
    grass
    gis
    modules

    we can do the same with keyword arguments, rewrite the above function: ::

        def f(*args, **kargs):
            for arg in args:
                print arg
            for key, value in kargs.items():
                print "%s = %r" % (key, value)

    now we can use the new function, with:

    >>> f('grass', 'gis', 'modules', os = 'linux', language = 'python')
    ...                                                  # doctest: +SKIP
    grass
    gis
    modules
    os = 'linux'
    language = 'python'

    or, as before we can, define a dictionary and give the dictionary to
    the function, like:

    >>> keywords = {'os' : 'linux', 'language' : 'python'}  # doctest: +SKIP
    >>> f(*words, **keywords)                            # doctest: +SKIP
    grass
    gis
    modules
    os = 'linux'
    language = 'python'

    In the Module class we heavily use this language feature to pass arguments
    and keyword arguments to the grass module.
    """
    def __init__(self, cmd, *args, **kargs):
        if isinstance(cmd, unicode):
            self.name = str(cmd)
        elif isinstance(cmd, str):
            self.name = cmd
        else:
            raise GrassError(
                "Problem initializing the module {s}".format(s=cmd))
        try:
            # call the command with --interface-description
            get_cmd_xml = Popen([cmd, "--interface-description"], stdout=PIPE)
        except OSError as e:
            print("OSError error({0}): {1}".format(e.errno, e.strerror))
            str_err = "Error running: `%s --interface-description`."
            raise GrassError(str_err % self.name)
        # get the xml of the module
        self.xml = get_cmd_xml.communicate()[0]
        # transform and parse the xml into an Element class:
        # http://docs.python.org/library/xml.etree.elementtree.html
        tree = fromstring(self.xml)

        for e in tree:
            if e.tag not in ('parameter', 'flag'):
                self.__setattr__(e.tag, GETFROMTAG[e.tag](e))

        #
        # extract parameters from the xml
        #
        self.params_list = [Parameter(p) for p in tree.findall("parameter")]
        self.inputs = TypeDict(Parameter)
        self.outputs = TypeDict(Parameter)
        self.required = []

        # Insert parameters into input/output and required
        for par in self.params_list:
            if par.input:
                self.inputs[par.name] = par
            else:
                self.outputs[par.name] = par
            if par.required:
                self.required.append(par.name)

        #
        # extract flags from the xml
        #
        flags_list = [Flag(f) for f in tree.findall("flag")]
        self.flags = TypeDict(Flag)
        for flag in flags_list:
            self.flags[flag.name] = flag

        #
        # Add new attributes to the class
        #
        self.run_ = True
        self.finish_ = True
        self.env_ = None
        self.stdin_ = None
        self.stdin = None
        self.stdout_ = None
        self.stderr_ = None
        diz = {
            'name': 'stdin',
            'required': False,
            'multiple': False,
            'type': 'all',
            'value': None
        }
        self.inputs['stdin'] = Parameter(diz=diz)
        diz['name'] = 'stdout'
        self.outputs['stdout'] = Parameter(diz=diz)
        diz['name'] = 'stderr'
        self.outputs['stderr'] = Parameter(diz=diz)
        self.popen = None
        self.time = None

        if args or kargs:
            self.__call__(*args, **kargs)
        self.__call__.__func__.__doc__ = self.__doc__

    def __call__(self, *args, **kargs):
        """Set module paramters to the class and, if run_ is True execute the
        module, therefore valid parameters are all the module parameters
        plus some extra parameters that are: run_, stdin_, stdout_, stderr_,
        env_ and finish_.
        """
        if not args and not kargs:
            self.run()
            return self

        #
        # check for extra kargs, set attribute and remove from dictionary
        #
        if 'flags' in kargs:
            for flg in kargs['flags']:
                self.flags[flg].value = True
            del (kargs['flags'])

        # set attributs
        for key in ('run_', 'env_', 'finish_', 'stdout_', 'stderr_'):
            if key in kargs:
                setattr(self, key, kargs.pop(key))

        # set inputs
        for key in ('stdin_', ):
            if key in kargs:
                self.inputs[key[:-1]].value = kargs.pop(key)

        #
        # check args
        #
        for param, arg in zip(self.params_list, args):
            param.value = arg
        for key, val in kargs.items():
            if key in self.inputs:
                self.inputs[key].value = val
            elif key in self.outputs:
                self.outputs[key].value = val
            elif key in self.flags:
                # we need to add this, because some parameters (overwrite,
                # verbose and quiet) work like parameters
                self.flags[key].value = val
            else:
                raise ParameterError('%s is not a valid parameter.' % key)

        #
        # check if execute
        #
        if self.run_:
            #
            # check reqire parameters
            #
            for k in self.required:
                if ((k in self.inputs and self.inputs[k].value is None) or
                    (k in self.outputs and self.outputs[k].value is None)):
                    msg = "Required parameter <%s> not set."
                    raise ParameterError(msg % k)
            return self.run()
        return self

    def get_bash(self):
        """Return a BASH rapresentation of the Module."""
        return ' '.join(self.make_cmd())

    def get_python(self):
        """Return a Python rapresentation of the Module."""
        prefix = self.name.split('.')[0]
        name = '_'.join(self.name.split('.')[1:])
        params = ', '.join([
            par.get_python() for par in self.params_list
            if par.get_python() != ''
        ])
        flags = ''.join([
            flg.get_python() for flg in self.flags.values()
            if not flg.special and flg.get_python() != ''
        ])
        special = ', '.join([
            flg.get_python() for flg in self.flags.values()
            if flg.special and flg.get_python() != ''
        ])
        #     pre name par flg special
        if flags and special:
            return "%s.%s(%s, flags=%r, %s)" % (prefix, name, params, flags,
                                                special)
        elif flags:
            return "%s.%s(%s, flags=%r)" % (prefix, name, params, flags)
        elif special:
            return "%s.%s(%s, %s)" % (prefix, name, params, special)
        else:
            return "%s.%s(%s)" % (prefix, name, params)

    def __str__(self):
        """Return the command string that can be executed in a shell"""
        return ' '.join(self.make_cmd())

    def __repr__(self):
        return "Module(%r)" % self.name

    @docstring_property(__doc__)
    def __doc__(self):
        """{cmd_name}({cmd_params})
        """
        head = DOC['head'].format(
            cmd_name=self.name,
            cmd_params=(
                '\n' +  # go to a new line
                # give space under the function name
                (' ' * (len(self.name) + 1))).join([
                    ', '.join(
                        # transform each parameter in string
                        [str(param) for param in line if param is not None])
                    # make a list of parameters with only 3 param per line
                    for line in zip_longest(*[iter(self.params_list)] * 3)
                ]),
        )
        params = '\n'.join([par.__doc__ for par in self.params_list])
        flags = self.flags.__doc__
        return '\n'.join([head, params, DOC['flag_head'], flags, DOC['foot']])

    def get_dict(self):
        """Return a dictionary that includes the name, all valid
        inputs, outputs and flags
        """
        dic = {}
        dic['name'] = self.name
        dic['inputs'] = [(k, v.value) for k, v in self.inputs.items()
                         if v.value]
        dic['outputs'] = [(k, v.value) for k, v in self.outputs.items()
                          if v.value]
        dic['flags'] = [flg for flg in self.flags if self.flags[flg].value]
        return dic

    def make_cmd(self):
        """Create the command string that can be executed in a shell

        :returns: the command string
        """
        skip = ['stdin', 'stdout', 'stderr']
        args = [
            self.name,
        ]
        for key in self.inputs:
            if key not in skip and self.inputs[key].value:
                args.append(self.inputs[key].get_bash())
        for key in self.outputs:
            if key not in skip and self.outputs[key].value:
                args.append(self.outputs[key].get_bash())
        for flg in self.flags:
            if self.flags[flg].value:
                args.append(str(self.flags[flg]))
        return args

    @mdebug(1, extra=_get_bash)
    def run(self):
        """Run the module

        :param node:
        :type node:

        This function will wait for the process to terminate in case
        finish_==True and sets up stdout and stderr. If finish_==False this
        function will return after starting the process. Use
        self.popen.communicate() of self.popen.wait() to wait for the process
        termination. The handling of stdout and stderr must then be done
        outside of this function.
        """
        if self.inputs['stdin'].value:
            self.stdin = self.inputs['stdin'].value
            self.stdin_ = PIPE

        cmd = self.make_cmd()
        start = time.time()
        self.popen = Popen(cmd,
                           stdin=self.stdin_,
                           stdout=self.stdout_,
                           stderr=self.stderr_,
                           env=self.env_)
        if self.finish_:
            stdout, stderr = self.popen.communicate(input=self.stdin)
            self.outputs['stdout'].value = stdout if stdout else ''
            self.outputs['stderr'].value = stderr if stderr else ''
            self.time = time.time() - start
            if self.popen.poll():
                raise CalledModuleError(returncode=self.popen.returncode,
                                        code=self.get_bash(),
                                        module=self.name,
                                        errors=stderr)
        return self