Summary
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.
Discussion
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:
value_table.setRow(0, "'c:/temp/land use.shp' 2")
Syntax
ValueTable ({columns})
Parameter | Explanation | Data Type |
columns | The number of columns. (The default value is 1) | Integer |
Properties
Property | Explanation | Data Type |
columnCount (Read Only) | The number of columns. | Integer |
rowCount (Read Only) | The number of rows. | Integer |
Method Overview
Method | Explanation |
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: |
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:
|
setValue (row, column, value) | Updates the value of a given row and column. |
Methods
addRow (value)
Parameter | Explanation | Data Type |
value | The row to be added. | Object |
exportToString ()
Return Value
Data Type | Explanation |
String | The string representation of the object. |
getRow (row)
Parameter | Explanation | Data Type |
row | The row index position. | Integer |
Return Value
Data Type | Explanation |
String | A row from the value table. |
getTrueValue (row, column)
Parameter | Explanation | Data Type |
row | The row index position. | Integer |
column | The column index position. | Integer |
Return Value
Data Type | Explanation |
String | The value of a given column and row. |
getValue (row, column)
Parameter | Explanation | Data Type |
row | The row index position. | Integer |
column | The column index position. | Integer |
Return Value
Data Type | Explanation |
String | The value of a given column and row. |
loadFromString (string)
Parameter | Explanation | Data Type |
string | The string representation of the object. | String |
removeRow (row)
Parameter | Explanation | Data Type |
row | The index position of the row to remove. | Integer |
setColumns (number_of_columns)
Parameter | Explanation | Data Type |
number_of_columns | The number of columns for the value table. | Integer |
setRow (row, value)
Parameter | Explanation | Data Type |
row | The index position of the row to update. | Integer |
value | The value to update the given row. | Object |
setValue (row, column, value)
Parameter | Explanation | Data Type |
row | The row index. | Integer |
column | The column index | Integer |
value | The value to update the given row and column. | Object |
Code sample
ValueTable example
Use ValueTable to hold feature class names and ranks for the Union tool.
import arcpy
# Set the workspace. List all of the feature classes in the dataset
arcpy.env.workspace = "c:/data/landbase.gdb/Wetlands"
feature_classes = arcpy.ListFeatureClasses()
# Create the value table for the Analysis Union tool with 2 columns
value_table = arcpy.ValueTable(2)
# Iterate through the list of feature classes
for fc in feature_classes:
# Update the value table with a rank of 2 for each record, except
# for BigBog
if fc.lower() != "bigbog":
value_table.addRow(fc + " 2")
else:
value_table.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
value_table.addRow("c:/data/landbase.gdb/land_use 2")
arcpy.Union_analysis(value_table, "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 os
import arcpy
# Set the output workspace
arcpy.env.workspace = arcpy.GetParameterAsText(1)
# Create a value table with 2 columns
value_table = arcpy.ValueTable(2)
# Set the values of the table with the contents of the first argument
value_table.loadFromString(arcpy.GetParameterAsText(0))
# Loop through the list of inputs
for i in range(0, value_table.rowCount):
# Validate the output name for the new workspace
name = value_table.getRow(i)
out_name = arcpy.ValidateTableName(os.path.basename(name))
# Copy the features to the new workspace
arcpy.CopyFeatures_management(name, out_name)