ValueTable (arcpy)

摘要

值表是一种灵活的对象，可用作多值参数的输入。它仅在创建此表的地理处理对象的生存时间内存在。

讨论

setRow 的值参数以空格分隔。所有含空格值参数中使用的值均必须用引号括起。在下例中，向包含两列的值表中分别添加了一个要素类和一个索引值：

value_table.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

代码实例

ValueTable 示例

使用 ValueTable 保存联合工具的要素类名称和等级。

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 示例 2

如果已将多值字符串作为参数传递到脚本，则可用其填充值表，以使提取各记录更为简便。以下示例将对此操作方法进行说明：

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 xrange(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)