Filter (arcpy)

Récapitulatif

The filter object allows you to specify the choices available for a parameter.

Discussion

L'objet filter vous permet de spécifier les choix disponibles pour un paramètre. Par exemple, vous pouvez définir un filtre de champ qui limite les choix uniquement aux champs de texte. Un filtre effectue trois tâches :

Il existe deux façons de spécifier des filtres :

Propriétés

PropriétéExplicationType de données
list
(Lecture/écriture)

If you do not want to filter values, set the list property to an empty list.

The datatype specified depends on the filter type (ValueList, Range, FeatureClass, File, Field, and Workspace).

String
type
(Lecture/écriture)

The type of filter (ValueList, Range, FeatureClass, File, Field, and Workspace). You can set the type of filter when dealing with Long and Double parameters. For other types of parameters, there is only one valid type of filter, so setting the type on these parameters is ignored. If you do not want to filter values, set the List property to an empty list.

String

Exemple de code

Filter example

An example of dynamically updating a Value List Filter containing a choice list of keywords. If the user enters "OLD_FORMAT" in the second parameter, the third parameter contains "POINT, LINE, and POLYGON". If "NEW_FORMAT" is entered, the third parameter contains three additional choices.

import arcpy

class ToolValidator:
    def __init__(self):
        self.params = arcpy.GetParameterInfo()

    def initializeParameters(self):
        return

    def updateParameters(self):
        # Provide default values for "file format type" and
        #  "feature type in file"
        if not self.params[1].altered:
            self.params[1].value = "OLD_FORMAT"
        if not self.params[2].altered:
            self.params[2].value = "POINT"

        # Update the value list filter of the "feature type in file"
        # parameter depending on the type of file (old vs. new format)
        # input
        if self.params[1].value == "OLD_FORMAT":
            self.params[2].filter.list = ["POINT", "LINE", "POLYGON"]
        elif self.params[1].value == "NEW_FORMAT":
            self.params[2].filter.list = ["POINT", "LINE", "POLYGON",
                                          "POINT_WITH_ANNO",
                                          "LINE_WITH_ANNO",
                                          "POLYGON_WITH_ANNO"]

        return

    def updateMessages(self):
        return
Filter example 2

An example where the Value List Filter in the second parameter changes based on the shape type found in the first parameter, a feature class.

def updateParameters(self):
    # Update the value list filter in the second parameter based
    # on the shape type in the first parameter
    string_filter = self.params[1].filter
    feature_class = self.params[0].value
    if feature_class:
        shape_type = arcpy.Describe(feature_class).shapeType
        if shape_type in ["Point", "Multipoint"]:
            string_filter.list = ["RED", "GREEN", "BLUE"]
        elif shape_type == "Polygon":
            string_filter.list = ["WHITE", "GRAY", "BLACK"]
        else:
            string_filter.list = ["ORANGE", "INDIGO", "VIOLET"]
    else:
        string_filter.list = ["RED", "GREEN", "BLUE"]

    # If the user hasn't changed the keyword value, set it to the
    # default value (first value in the value list filter).
    if not self.params[1].altered:
        self.params[1].value = string_filter.list[0]

    return

Thèmes connexes

4/26/2014