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How does the listlayers method work in ArcGIS?
The listLayers method on the Map Class returns index values that are generated from top to bottom as they appear in the table of contents or the way they appear in a layer file. The same applies if a group layer is within another group layer.
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):).
What is the LONGNAME of a layer in ArcGIS Pro?
A layer’s longName value will include the group name in addition to the layer name. For example, a layer named Layer1 in a group layer named Group1 will have a longName value of Group1\\Layer1.
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 to update data sources with arcpy.mapping?
Methods are available with the arcpy.mapping scripting environment that make it possible to automate these changes without even having to open a map document. You have control of updating data sources for individual layers, or you can update all layers at once that have a common workspace.
Are there properties not exposed to ArcPy scripting environment?
Not all layer properties are accessible through the Layer object. There are many properties available in the ArcMap Layer Properties dialog box that are not exposed to the arcpy scripting environment (for example, display properties, field aliases, selection symbology, and so on).