Is there way to generate unique values in ArcPy?

Is there way to generate unique values in ArcPy?

While there are certainly other ways to do this either in ArcGIS (Desktop or Pro) or through SQL we’ll focus specifically on the needs of Python programmers working with Arcpy who need to generate a list of unique values for an attribute field.

What does for row in cursor mean in ArcPy?

This is called set comprehension. The for row in cursor snippet initiates a for loop through each record in the feature class. The row [0] snippet simply indicates that the attribute field located at position 0 (FireType) is extracted for the current row. Notice that the entire snippet is surround by curly braces {row [0] for row in cursor} .

What can you do with ArcPy and NumPy?

Numpy is a library for the Python programming language, adding support for large, multi-dimensional arrays and matrices, along with a large collection of high-level mathematical functions to operate on these arrays. Arcpy includes functions that allow you to move datasets between GIS and numpy structures.

Can you create a list of unique attribute values in Python?

In this article we’ll examine how you can use Python with Arcpy and Numpy to create a list of unique attribute values from a field.

How to add features to list in ArcPy?

You can use the ADD_TO_SELECTION even if there are no features selected, it will create a new selection on the first iteration. I had this same problem, and anticpated many sizes of the list to be used. What I did was change my list to a string then removed brackets:

How to select features by attribute in Python?

I am trying to complete a select by attribute in Python but based on the query of whether an attribute is present in a list. but that approach returns an invalid expression error. In the past, I’ve had to use more complicated sytax for this type of query, such as: but an adaptation of this snippet doesn’t seem to work for me either, ie.:

How to get a parameter into an ArcPy script?

Before we can do anything with our tool and our nice interface for it, we need to get those parameters into our script. This can be done by using arcpy’s function called .GetParameterAsText () where the index value of the parameter is passed to the function (where number 0 is the first parameter).

How to replace certain characters within a string with ArcPy?

How to replace certain characters within a string with ArcPy? I have a list of files where the last digits of the number all need to be changed in a new column. Only thing is there are files with ‘H1’ at the beginning of the name, and those files will be affected with this code. I need to make sure that ONLY the final characters change.

What does row [ 0 ] mean in ArcPy?

The row [0] snippet simply indicates that the attribute field located at position 0 (FireType) is extracted for the current row. Notice that the entire snippet is surround by curly braces {row [0] for row in cursor} . This is called set comprehension and will automatically eliminate duplicates in your values .

How to get a list of labelclasses in ArcGIS?

The labelClasses property will return a list of LabelClass objects. To reference a specific LabelClass object, it will be necessary to loop through each item in the list or provide a specific index number. Provides the ability to get or set a layer’s individual label class name.

Why is the label expression not working in ArcPy?

If the SQL query is not updated, layers may fail to draw. For more information on these special cases, refer to the Updating and fixing data sources within arcpy.mapping topic. The label expression is either using the VBScript, JScript or Python parsers.