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Parameter

サマリー

Every tool parameter has an associated Parameter object with properties and methods that are useful in tool validation.

ディスカッション

Although many Parameter object properties are read/write, most of them can only be set or modified when you initially create or modify the object. The following properties establish the characteristics of a parameter and cannot be modified during validation methods (such as updateMessages and updateParameters):

  • category

  • controlCLSID

  • datatype

  • direction

  • displayName

  • displayOrder

  • multiValue

  • name

  • parameterDependencies

  • parameterType

構文

Parameter({name}, {displayName}, {direction}, {datatype}, {parameterType}, {enabled}, {category}, {symbology}, {multiValue})

名前 説明 データ タイプ

name

(オプション)

The parameter name.

The default value is None.

String

displayName

(オプション)

The parameter label as shown in the Geoprocessing pane.

The default value is None.

String

direction

(オプション)

Specifies the direction of the parameter.

The default value is Input.

String

datatype

(オプション)

The data type of the parameter.

Learn more about geoprocessing data types.

The default value is GPString.

String

parameterType

(オプション)

Specifies the parameter type.

The default value is Required.

String

enabled

(オプション)

Specifies whether the parameter is visible in the Geoprocessing pane.

The default value is True.

Boolean

category

(オプション)

The category of the parameter.

The default value is None.

String

symbology

(オプション)

The path to a layer file (.lyrx or .lyr) used for drawing the output.

The default value is None.

String

multiValue

(オプション)

Specifies whether the parameter is a multivalue parameter.

The default value is False.

Boolean

プロパティ

名前 説明 データ タイプ

altered

(読み取り専用)

Specifies whether the user has modified the value.

Boolean

category

(読み取り/書き込み)

The category of the parameter.

String

charts

(読み取り/書き込み)

A list of Chart objects that are added to an output parameter.

Object

columns

(読み取り/書き込み)

The structure of the columns in a Value Table parameter.

The columns are organized in a list of lists, with each inner list representing the column data type, column name, and an optional read-only value. If the read-only value is set to ReadOnly, the column cannot be modified by the user.

import arcpy
param = arcpy.Parameter()
param.datatype = "GPValueTable"
param.columns = [["GPFeatureLayer", "Features"], ["GPLong", "Ranks"]]

String

controlCLSID

(読み取り/書き込み)

A class identifier that can be used to override the default control for the data type.

Learn more about parameter controls

String

datatype

(読み取り/書き込み)

The data type of the parameter.

Learn more about geoprocessing data types.

String

defaultEnvironmentName

(読み取り/書き込み)

The name of the geoprocessing environment that will be used to set the parameter's default value.

String

direction

(読み取り/書き込み)

Specifies the direction of the parameter.

  • Input—An input parameter

  • Output—An output parameter

String

displayName

(読み取り/書き込み)

The parameter label as shown in the Geoprocessing pane.

String

displayOrder

(読み取り/書き込み)

The order in which a parameter displays in the Geoprocessing pane. This may be different from the order the parameters are accessed from Python.

Integer

enabled

(読み取り/書き込み)

Specifies whether the parameter is visible in the Geoprocessing pane.

Boolean

filter

(読み取り専用)

The filter to apply to values in the parameter.

Filter

filters

(読み取り/書き込み)

Similar to the filter property, but it is used to support value table and composite parameters.

For a value table parameter, set the filters property, and define a Filter object using the list and optional type for each column in the value table.

class ValueTableSampleTool(object):
    # __init__ left out to simplify example

    def getParameterInfo(self):
        in_fc = arcpy.Parameter(
            name='in_features',
            displayName='Input Features',
            datatype='GPFeatureLayer',
            direction='Input',
            parameterType='Required')

        vt = arcpy.Parameter(
            name='summary_fields',
            displayName='Summary fields',
            datatype='GPValueTable',
            direction='Input',
            parameterType='Optional')

        vt.parameterDependencies = [in_fc.name]
        vt.columns = [
          ['Field', 'Field'],
          ['GPString', 'Statistic'],
          ['GPDouble', 'Multiplier']
        ]
        vt.filters[0].list = ['Double', 'Float', 'Short', 'Long']
        vt.filters[1].type = 'ValueList'
        vt.filters[1].list = ['SUM', 'MIN', 'MAX', 'MEAN']
        vt.filters[2].type = 'Range'
        vt.filters[2].list = [0, 10]

        return [in_fc, vt]

For a composite parameter, set the filters property, and define a Filter object using a list for each data type in the composite parameter.

class CompositeSampleTool(object):
    # __init__ left out to simplify example

    def getParameterInfo(self):
        composite = arcpy.Parameter(
            name="composite_example",
            displayName="Composite Example",
            datatype=["GPString", "GPDouble"],
            parameterType="Optional",
            direction="Input",
            multiValue=True)

        composite.filters = ["CodedValue", "Range"]
        composite.filters[0].list = ["MIN", "MAX"]
        composite.filters[1].list = [1, 100]

        return [composite]

Filter

hasBeenValidated

(読み取り専用)

Specifies whether the internal validation routine has checked the parameter.

Boolean

message

(読み取り専用)

The message to be displayed to the user.

String

multiValue

(読み取り/書き込み)

Specifies whether the parameter is a multivalue parameter.

Boolean

name

(読み取り/書き込み)

The parameter name.

String

parameterDependencies

(読み取り/書き込み)

A list of indexes of each dependent parameter.

In a script tool, parameterDependencies is set with a list of parameter indexes; in a Python toolbox tool, parameterDependencies is set with a list of parameter names.

Integer

parameterType

(読み取り/書き込み)

Specifies the parameter type.

  • Required—The tool cannot be run until a value has been provided.

  • Optional—The parameter does not require a value.

  • Derived—The parameter returns an output value. Derived parameters are always output parameters and are not shown in the Geoprocessing pane.

For derived parameters, set the direction property to Output and the parameterType property to Derived.

In validation, the parameterType value cannot be dynamically modified. However, it may be necessary for a parameter to behave as a required parameter or an optional parameter depending on other parameter settings. If this is the case, set the parameter as optional. Then, in the validation updateMessages method, use the Parameter setIDMessage method with message ID 530 or 735. Using message ID 530 or 735 will cause an optional parameter to behave as a required parameter.

String

schema

(読み取り専用)

The schema of the output dataset.

Schema

symbology

(読み取り/書き込み)

The path to a layer file (.lyrx or .lyr) used for drawing the output.

String

value

(読み取り/書き込み)

The value of the parameter.

Object

valueAsText

(読み取り専用)

The value of the parameter as a string.

String

values

(読み取り/書き込み)

The values of a Value Table parameter, which is set using a list of lists.

Object

方法

clearMessage()

Clears any message text and sets the status to informative (no error or warning).

hasError()

Returns True if the parameter contains an error.

To evaluate whether a parameter has an error, call hasError from the tool validation's updateMessages method.

戻り値

データ タイプ 説明

Boolean

True if the parameter contains an error.

hasWarning()

Specifies whether the parameter contains a warning.

戻り値

データ タイプ 説明

Boolean

Returns whether the parameter contains a warning.

isInputValueDerived()

Specifies whether the tool is validated inside a model and the input value is the output of another tool in the model.

戻り値

データ タイプ 説明

Boolean

Returns whether the tool is validated inside a model and the input value is the output of another tool in the model.

setErrorMessage(message)

Sets a parameter as having an error with the supplied message. Tools do not execute if any of the parameters have an error.

名前 説明 データ タイプ

message

The string to be added as an error message to the geoprocessing tool messages.

String

setIDMessage(message_type, message_ID, {add_argument1}, {add_argument2})

Sets a parameter as having a system message.

名前 説明 データ タイプ

message_type

Defines whether the message will be an error or a warning.

  • ERROR—The message will be an error message.

  • WARNING—The message will be a warning message.

String

message_ID

The message ID allows you to reference existing system messages.

Integer

add_argument1

(オプション)

Depending on which message ID is used, an argument may be necessary to complete the message. Common examples include dataset or field names. The data type is variable depending on the message.

Object

add_argument2

(オプション)

Depending on which message ID is used, an argument may be necessary to complete the message. Common examples include dataset or field names. The data type is variable depending on the message.

Object

setWarningMessage(message)

Sets a parameter as having an error with the supplied message. Unlike errors, tools will execute with warning messages.

名前 説明 データ タイプ

message

The string to be added as a warning message to the geoprocessing tool messages.

String

コードのサンプル

Parameter example

Enable or disable a parameter in a ToolValidator class.

def updateParameters(self):
    # If the option to use a weights file ("Get Spatial Weights From File")
    # is selected, enable the parameter for specifying the file;
    # otherwise, disable it.

    if self.params[3].value == "Get Spatial Weights From File":
        self.params[8].enabled = True
    else:
        self.params[8].enabled = False

    return
Parameter example 2

Set a default value for a parameter in a ToolValidator class.

def updateParameters(self):
    # Set the default distance threshold to 1/100 of the larger of
    # the width or height of the extent of the input features.  Do
    # not set if there is no input dataset yet, or the user has set
    # a specific distance (Altered is true).

    if self.params[0].value:
        if not self.params[6].altered:
            extent = arcpy.Describe(self.params[0].value)
        width = extent.XMax - extent.XMin
        height = extent.YMax - extent.YMin

        if width < height:
            self.params[6].value = width / 100
        else:
            self.params[6].value = height / 100

        return
Parameter example 3

Set a custom error message for a parameter in a ToolValidator class.

def updateMessages(self):
    self.params[6].clearMessage()

    # Check whether the threshold distance contains a value of
    # zero and the user has specified a fixed distance band.
    if self.params[6].value <= 0:
        if self.params[3].value == "Fixed Distance Band":
            self.params[6].setErrorMessage(
                "Zero or a negative distance is invalid when "
                "using a fixed distance band. Please use a "
                "positive value greater than zero.")
        elif self.params[6].value < 0:
            self.params[6].setErrorMessage(
                "A positive distance value is required when "
                "using a fixed distance band. Be sure to specify "
                "a distance.")

    return