Python for ArcGIS：将文本字段添加到形状文件，然后搜索一个字段，如果满足条件，则更新另一个字段

Question

我正在自学 Python (2.7) for ArcGIS (10.8)。我有这个问题：

Write a script that adds a text field to the roads.shp feature class called FERRY and populates this field with YES and NO values, depending on the value of the FEATURE field.

在尝试弄清楚并通过互联网查看后，我得到了这个脚本：

from arcpy
from arcpy import env
env.workspace = "C/esriPress/Python/Data/Exercise07/Results" # Set workspace
env.overwriteOutput = True   # overwriting outputs
fc = "roads.shp" # input feature class

newfield = "FERRY"  # new field to be created
fieldtype = "TEXT"  # type of the field that is going to be created
fieldname = arcpy.ValidateFieldName(newfield)  # to determine whether a specific name is valid or not
field_length = 3 # Lenght of th new field to be created
fieldlist = ListFields(fc)  # list the fields in 'fc', it returns a reference number of each object, not the object name.
fieldnames = [] # Create an empty list


# Check whether 'newfield' already exist or not; if not, create it
for field in fieldlist: # For each element in 'fieldlist'...
    fieldnames.append(field.name) #...add in the empty list 'fieldnames' the field name
if fieldname not in fieldnames: # if 'fieldname' don't exists in 'fiednames'...
    arcpy.AddField_management(fc, fieldname, fieldtype, field_length)  # ...Create 'fieldname' in 'fc' with length = 3
    print ("New field has been added")
else:
    print ("Field name already exists.")


# Search in the one field and update other field
fields = ['FEATURE', newfield]  # Create a list that contains the field we apply condition, and  the field we going to update
with arcpy.da.UpdateCursor(fc, fields) as cursor: # Setting the cursor; notice the cursor is made up of two fields
    for row in cursor: # For each row in cursor...
        if row[0] == "Ferry Crossing": #...if row in field 1 = "Ferry Crossing'...
            row[1] = "YES" #... Set that row in field 2 to 'Yes'
        else: # Otherwise...
            row[1] = "NO" # ....Set that row in field 2 to 'No'...
        cursor.updateRow(row) # Update cursor
print ("New field has been added" % newfield)

        else:
            row[1] = "NO"
        cursor.updateRow(row)
print ("Field name already exists" % newfield)

但是，当我在 PythonWin 2.7.16 中运行脚本时，我收到此错误消息：

Failed to run script - syntax error - invalid syntax

我的脚本有什么问题？这是正确的方法吗？

Answer 1

您似乎有 2 个 else 块和一个额外的 cursor.updateRow(row)。因此，您的 print 语句没有正确缩进。尝试运行以下 Update Cursor:

import arcpy

fc = '/path/to/your/geodatabase.gdb/feature_class'

# Add field
arcpy.AddField(fc, "FERRY", field_type = "TEXT")

# Update attributes based on a condition
# Note row[0] is "FEATURE" and row[1] is "FERRY"
with arcpy.da.UpdateCursor(fc, ["FEATURE", "FERRY"]) as cursor:
    for row in cursor:
        if row[0] == "ADD YOUR CONDITION HERE":
            row[1] = "YES"
        else:
            row[1] = "NO"
        cursor.updateRow(row)

Python for ArcGIS：将文本字段添加到形状文件，然后搜索一个字段，如果满足条件，则更新另一个字段

Python for ArcGIS: add a text field to a shape file, then search one field and if meets a condition, update another field

arcgis

arcpy