ValueTable

摘要

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.

讨论

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")

语法

ValueTable ({columns})

参数	说明	数据类型
columns	The number of columns. (默认值为 1)	Integer

属性

属性	说明	数据类型
columnCount （只读）	The number of columns.	Integer
rowCount （只读）	The number of rows.	Integer

方法概述

方法	说明
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)	Updates a given row within the value table. 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")
setValue (row, column, value)	Updates the value of a given row and column.

方法

addRow (value)

参数	说明	数据类型
value	The row to be added.	Object

exportToString ()

返回值

数据类型	说明
String	The string representation of the object.

getRow (row)

参数	说明	数据类型
row	The row index position.	Integer

返回值

数据类型	说明
String	A row from the value table.

getTrueValue (row, column)

参数	说明	数据类型
row	The row index position.	Integer
column	The column index position.	Integer

返回值

数据类型	说明
String	The value of a given column and row.

getValue (row, column)

参数	说明	数据类型
row	The row index position.	Integer
column	The column index position.	Integer

返回值

数据类型	说明
String	The value of a given column and row.

loadFromString (string)

参数	说明	数据类型
string	The string representation of the object.	String

removeRow (row)

参数	说明	数据类型
row	The index position of the row to remove.	Integer

setColumns (number_of_columns)

参数	说明	数据类型
number_of_columns	The number of columns for the value table.	Integer

setRow (row, value)

参数	说明	数据类型
row	The index position of the row to update.	Integer
value	The value to update the given row.	Object

setValue (row, column, value)

参数	说明	数据类型
row	The row index.	Integer
column	The column index	Integer
value	The value to update the given row and column.	Object

代码示例

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