Field

Zusammenfassung

The field object represents a column in a table. A field has many properties, the most obvious ones being its name and its type.

Diskussion

Field properties can be accessed through the ListFields and Describe functions.

Updating a field property only updates the field object, no changes are made to the actual field in the table or feature class.

Syntax

 Field  ()

Eigenschaften

EigenschaftErläuterungDatentyp
aliasName
(Lesen und schreiben)

The alias name of the field.

String
baseName
(Lesen und schreiben)

The unqualified field name.

String
defaultValue
(Lesen und schreiben)

The default value of the field.

Variant
domain
(Lesen und schreiben)

The name of the associated domain.

String
editable
(Lesen und schreiben)

Specifies whether the field is editable.

Boolean
isNullable
(Lesen und schreiben)

Specifies whether the field can contain null values.

Boolean
length
(Lesen und schreiben)

The length of the field.

Integer
name
(Lesen und schreiben)

The name of the field.

String
precision
(Lesen und schreiben)

The precision for field values.

For fields of type Date, the precision can be either 0 or 1.

  • 0—A regular date field. Data will be stored to the second (1/60 of a minute).
  • 1—A high precision date field. Data will be stored to the millisecond (1/1000 of a second).

Integer
required
(Lesen und schreiben)

Specifies whether the field is required. A required field cannot be deleted.

Boolean
scale
(Lesen und schreiben)

The scale of the field.

Integer
type
(Lesen und schreiben)

Specifies the field type.

  • BlobThe field type will be BLOB.
  • BigIntegerThe field type will be Big Integer.
  • DateThe field type will be Date.
  • DateOnlyThe field type will be Date Only.
  • DoubleThe field type will be Double.
  • GeometryThe field type will be Geometry.
  • GlobalIDThe field type will be Global ID.
  • GuidThe field type will be GUID.
  • IntegerThe field type will be Integer (Long Integer).
  • OIDThe field type will be Object ID.
  • RasterThe field type will be Raster.
  • SingleThe field type will be Single (Float).
  • SmallIntegerThe field type will be Small Integer (Short Integer).
  • StringThe field type will be String (Text).
  • TimeOnlyThe field type will be Time Only.
  • TimestampOffsetThe field type will be Timestamp Offset.
Hinweis:

The Field object's type property values are not an exact match for the keywords used by the Add Field tool's field_type parameter. Despite this, all of the Field object's type values are acceptable values as input to this parameter. The different field types are mapped as follows:

  • Integer to LONG
  • String to TEXT
  • SmallInteger to SHORT

String

Codebeispiel

Field example

Display field properties for the specified feature class.

import arcpy

feature_class = "c:/data/counties.shp"

# Create a list of fields using the ListFields function
fields = arcpy.ListFields(feature_class)

# Iterate through the list of fields
for field in fields:
    # Print field properties
    print("Field:       {0}".format(field.name))
    print("Alias:       {0}".format(field.aliasName))
    print("Type:        {0}".format(field.type))
    print("Is Editable: {0}".format(field.editable))
    print("Required:    {0}".format(field.required))
    print("Scale:       {0}".format(field.scale))
    print("Precision:   {0}".format(field.precision))

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