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How to return a list object in ArcPy?
ListLayers always returns a Python list object even if only one layer is returned. In order to return a Layer object, an index value must be used on the list (e.g., lyr = arcpy.mapping.ListLayers (mxd)). For loops on a list provide an easy mechanism to iterate through each item in a list (e.g., for lyr in arcpy.mapping.ListLayers (mxd):).
How to create a list of feature classes in ArcPy?
List all of the feature classes that start with ‘G’ # arcpy.env.workspace = “D:/St_Johns/data.gdb” fcs = arcpy.ListFeatureClasses(“G*”) The list can also be restricted to match certain data properties, such as only polygon feature classes, integer fields, or coverage datasets. This is what the type parameter is used for in all functions.
Why do I need for loops in ArcPy?
For loops on a list provide an easy mechanism to iterate through each item in a list (e.g., for lyr in arcpy.mapping.ListLayers (mxd): ). When working with layer files, the data_frame parameter should not be used because layer files don’t support data frames; if it is, it will be ignored.
What happens to the listfields in ArcGIS Pro?
The returned list can be limited with search criteria for name and field type and will contain field objects. The specified feature class or table with the fields to be returned. Limits the results returned. If a value is not specified, all values are returned. The wildcard is not case sensitive. Represents zero or more characters.
How to return list of layers in Python?
Returns a Python list of Layer objects that exist within a map document ( .mxd ), a data frame within a map document, or layers within a layer ( .lyr) file. ListLayers always returns a Python list object even if only one layer is returned.
Why is data _ frame not used in listlayers?
When working with layer files, the data_frame parameter should not be used because layer files don’t support data frames; if it is, it will be ignored. The Layer () function is for referencing layer ( .lyr) files stored on disk. Group layers are treated just like layers.
How does the arcpy.mapping scripting environment work?
Map documents that contain these layers will prompt the user to enter the appropriate information while the document is opening. The arcpy.mapping scripting environment will by default suppress these dialog boxes during execution, but that means that the layers will be treated as though they have broken data sources.
Where do I find the mapdocument object in ArcGIS?
The MapDocument object provides access to most of the map document properties found in the Map Document Properties dialog box in ArcMap ( File > Map Document Properties ). The object also contains methods for managing map document thumbnails and methods for saving map documents that are found within the ArcMap File menu.
Which is the first object reference in ArcPy?
The MapDocument object is usually one of the first object references created in a map automation script because it is a required parameter for many of the arcpy.mapping functions.
Returns a Python list of layout elements that exist within a map document ( .mxd) layout. ListLayoutElements always returns a Python list object even if only one page element is returned. In order to return an element object, an index value must be used on the list (e.g., elm = arcpy.mapping.ListLayoutElements (mxd) [0] ).
Where do you find listlayoutelements in ArcMap?
ListLayoutElements only returns elements from a page layout and not map annotation elements that may exist within a data frame. Each page element has a name property that can be set within the element properties dialog box within ArcMap (located on the Size and Position tab).
How to get a list of textelements in ArcGIS?
It is necessary to then iterate through each item in the list or specify an index number to reference a specific page element object. To return a list of TextElements only, use the TEXT_ELEMENT constant for the element_type parameter. A wildcard can also be used to further refine the search based on the element name.
How to return a list of legendelements in ArcGIS?
The ListLayoutElements function returns a Python list of page layout element objects. It is necessary to then iterate through each item in the list or specify an index number to reference a specific page element object. To return a list of only LegendElements, use the LEGEND_ELEMENT constant for the element_type parameter.
What are the parameters for the ArcPy tool?
One of the parameters for the tool is an input raster file, which I’ve set (using the properties of the tool within the toolbox) to be a Raster Layer.