ValueTable (arcpy)

Zusammenfassung

A value table is a flexible object that can be used as input for a multivalue parameter. It exists only during the lifetime of the geoprocessing object that created it.

Diskussion

setRow's value argument is space delimited. Any value used in the value argument that contains spaces must be enclosed in quotations. In the following example, a value table with two columns has a feature class and an index value added:

vtab.setRow(0, "'c:/temp/land use.shp' 2")

Syntax

ValueTable ({columns})

Parameter	Erläuterung	Datentyp
columns	The number of columns. (Der Standardwert ist 1)	Integer

Eigenschaften

Eigenschaft	Erläuterung	Datentyp
columnCount (Schreibgeschützt)	The number of columns.	Integer
rowCount (Schreibgeschützt)	The number of rows.	Integer

Methodenübersicht

Methode	Erläuterung
addRow (value)	Adds a row to the value table. addRow's value argument is space-delimited. Any value used in the value argument that contains spaces must be enclosed in quotations. In the following example, a value table with two columns has a feature class and an index value added: vtab.addRow("'c:/temp/land use.shp' 2")
exportToString ()	Exports the object to its string representation.
getRow (row)	Gets a row from the value table.
getTrueValue (row, column)	Gets value from a given column and row.
getValue (row, column)	Gets value from a given column and row.
loadFromString (string)	Restore the object using its string representation. The exportToString method can be used to create a string representation.
removeRow (row)	Deletes a row from the value table.
setColumns (number_of_columns)	Sets the number of columns for the value table.
setRow (row, value)	Aktualisiert die angegebene Zeile in der Wertetabelle. Das Werteargument für "setRow" wird durch Leerzeichen getrennt. Werte im Werteargument, die Leerzeichen enthalten, müssen in Anführungszeichen eingeschlossen werden. Im folgenden Beispiel enthält eine Wertetabelle mit zwei Spalten eine Feature-Class und einen hinzugefügten Indexwert: vtab.setRow(0, "'c:/temp/land use.shp' 2")
setValue (row, column, value)	Aktualisiert den Wert der angegebenen Spalte und Zeile.

Methoden

addRow (value)

Parameter	Erläuterung	Datentyp
value	The row to be added.	Object

exportToString ()

Rückgabewert

Datentyp	Erläuterung
String	The string representation of the object.

getRow (row)

Parameter	Erläuterung	Datentyp
row	The row index position.	Integer

Rückgabewert

Datentyp	Erläuterung
String	A row from the value table.

getTrueValue (row, column)

Parameter	Erläuterung	Datentyp
row	The row index position.	Integer
column	The column index position.	Integer

Rückgabewert

Datentyp	Erläuterung
String	The value of a given column and row.

getValue (row, column)

Parameter	Erläuterung	Datentyp
row	The row index position.	Integer
column	The column index position.	Integer

Rückgabewert

Datentyp	Erläuterung
String	The value of a given column and row.

loadFromString (string)

Parameter	Erläuterung	Datentyp
string	The string representation of the object.	String

removeRow (row)

Parameter	Erläuterung	Datentyp
row	The index position of the row to remove.	Integer

setColumns (number_of_columns)

Parameter	Erläuterung	Datentyp
number_of_columns	The number of columns for the value table.	Integer

setRow (row, value)

Parameter	Erläuterung	Datentyp
row	The index position of the row to update.	Integer
value	The value to update the given row.	Object

setValue (row, column, value)

Parameter	Erläuterung	Datentyp
row	The row index.	Integer
column	The column index	Integer
value	The value to update the given row and column.	Object

Codebeispiel

ValueTable example

Use ValueTable to hold feature class names and ranks for the Union tool.

import arcpy
from arcpy import env

# Set the workspace. List all of the feature classes in the dataset
#
env.workspace = "C:/Data/Landbase.gdb/Wetlands"
fcs = arcpy.ListFeatureClasses()

# Create the value table for the Analysis Union tool with 2 columns
#
vtab = arcpy.ValueTable(2)

# Iterate through the list of feature classes
#
for fc in fcs:
    # Update the value table with a rank of 2 for each record, except    
    #   for BigBog
    #
    if fc.lower() <> "bigbog":
       vtab.addRow(fc + " 2")
    else:
       vtab.addRow(fc + " 1")

# Union the wetlands feature classes with the land use feature class to create
#   a single feature class with all of the wetlands and land use data
#
vtab.addRow("C:/Data/Landbase.gdb/land_use 2")
arcpy.Union_analysis(vtab, "C:/Data/Landbase.gdb/wetlands_use")

ValueTable example 2

A value table can be populated with a multivalue string that has been passed to a script as an argument, making it easy to extract each record. The example below shows how to do this:

import arcpy
from arcpy import env
import os

# Set the output workspace
#
env.workspace = arcpy.GetParameterAsText(1)

# Create a value table with 2 columns
#
vtab = arcpy.ValueTable(2)

# Set the values of the table with the contents of the first argument
#
vtab.loadFromString(arcpy.GetParameterAsText(0))
x = 1

# Loop through the list of inputs
#
while x < vtab.rowCount:
    # Validate the output name for the new workspace
    #
    name = vtab.getRow(x)
    out_name = arcpy.ValidateTablename(os.path.basename(name))

    # Copy the features to the new workspace
    #
    arcpy.CopyFeatures_management(name, out_name)
    x += 1