Using fields and indexes

When described, feature classes and tables have a fields property that returns a list of Field objects and an indexes property that returns a list of Index objects. Each field or index object has a number of properties that can be used to explore the object. Alternatively, the ListFields and ListIndexes functions can be used to create the same lists.

List functions

ListFields(dataset, wild_card, field_type)	Returns a list of fields found in the input value
ListIndexes(dataset, wild_card)	Returns a list of attribute indexes found in the input value

The following example shows how to create a field list and loop through the contents to find a specific field.

import arcpy

fc = 'D:/St_Johns/data.gdb/roads'

# Get a list of field objects
fields = arcpy.ListFields(fc, 'Flag')

for field in fields:
    # Check the field name, perform a calculation when finding the field 'Flag'
    if field.name == 'Flag':
        # Set the value for the field and exit loop
        arcpy.CalculateField_management(fc, 'Flag', '1')
        break

The properties of the field and index objects are listed below:

Field properties

Property	Explanation
name	The name of the field.
aliasName	The alias name of the field.
domain	The name of the associated domain.
editable	True, if the field is editable.
isNullable	True, if the field is nullable.
required	True, if the field is required.
length	The field's length.
type	SmallInteger, Integer, Single, Double, String, Date, OID, Geometry, BLOB.
scale	The field's scale.
precision	The field's precision.

Index properties

Property	Explanation
name	The name of the index.
isAscending	True, if the index sorts in ascending order.
isUnique	True, if the index is unique.
fields	A list of Field objects. This is the same as using Describe fields property.

Tip:

ListFields and ListIndexes can be used to limit the results based on name and type.