GEOM 73 - Python Quiz 3

Frage 1 von 10

1

Which cursors of the arcpy.da module can be used to work with geometry objects using SHAPE@?

Wähle eine der folgenden:

SearchCursor, UpdateCursor, and InsertCursor
InsertCursor only
SearchCursor only
UpdateCursor only
UpdateCursor and InsertCursor

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Frage 2 von 10

1

Which of the following is not a geometry token in ArcPy?

Wähle eine der folgenden:

SHAPE@
SHAPE@CENTROID
SHAPE@XY
SHAPE@LENGTH

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Frage 3 von 10

1

What is the main reason to use geometry tokens instead of SHAPE@?

Wähle eine der folgenden:

Working with the full geometry objects of large datasets can be very slow
You only need SHAPE@ to create new features, not to read properties of existing ones
Geometry tokens give you access to the individual vertices of geometry objects, while SHAPE@ only gives you the entire geometry object
Some feature classes do not have a SHAPE field and using geometry tokens is the only option

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Frage 4 von 10

1

When using geometry tokens in a search cursor for single part polylines and polygons, what does the search cursor return for each row in the feature attribute table?

Wähle eine der folgenden:

an array of point objects
an array containing an array of point objects
a list of point objects
a list containing a list of point objects

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Frage 5 von 10

1

Consider the following script, in particular line 8 that uses getPart (0):

import arcpy
from arcpy import env
env.workspace = "C:/Data"
fc = "roads.shp"
cursor = arcpy.da.SearchCursor (fc, ["OID@", "SHAPE@"])
for row in cursor:
print ("Feature {0}: ".format (row[0]))
for point in row[1].getPart (0):
print ("{0}, {1}".format (point.X, point.Y))

Why is getPart (0) needed here, even if the features are all single part?

Wähle eine der folgenden:

For polylines and polygons, the cursor returns the parts of a geometry object as an array, so for single part features you need to get the first (and only) part
If you don't use getPart, all vertices for the entire feature class would print together and you would not be able to tell which vertices belong to which feature.
The use of getPart makes it possible to use the same script for point, polyline and polygon features.
All geometry objects consist of arrays of points, so get at the individual points you need to examine the parts.

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Frage 6 von 10

1

Which property(ies) of a geometry objects is (are) used to determine whether a specific feature is multipart or single part?

Wähle eine oder mehr der folgenden:

partCount
type
isMultipart
pointCount
shapeType

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Frage 7 von 10

1

Some polygon features contain 'holes'. When you work with geometry objects for such polygons, how can you determine whether these holes are present?

Wähle eine der folgenden:

the geometry property ringCount is greater than 1 for polygons with holes
you can use the geometry property isExterior to determine whether an array of point objects is an exterior or interior ring
the shapeType property of the geometry object is MultiPatch instead of Polygon
the array of point objects for a feature contains 'null point objects' which seperate the exterior and interior rings

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Frage 8 von 10

1

Consider a scenario where you write a script to create a new polyline out of a text file with coordinates for the vertices. You will need to use a cursor object to create new geometry objects. Which of the following is the correct line of code to set up your cursor object?

Wähle eine der folgenden:

cursor = arcpy.da.UpdateCursor(fc, ["SHAPE@"])
cursor = arcpy.da.InsertCursor(fc, "SHAPE@XY")
cursor = arcpy.da.InsertCursor(fc, "SHAPE@")
cursor = arcpy.da.UpdateCursor(fc, ["SHAPE@XY"])
cursor = arcpy.da.InsertCursor (fc, ["SHAPE@XY"])
cursor = arcpy.da.UpdateCursors(fc, ["SHAPE@XY"])

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Frage 9 von 10

1

Consider the following script to print the coordinates of the vertices of the features of a feature class.

import arcpy

from arcpy import env

env.workspace = "C:/Data"

fc = "features.shp"

cursor = arcpy.da.SearchCursor(fc, ["OID@", "SHAPE@"])

for row in cursor:

print ("Feature {0}: ".format(row[0]))

partnum = 0

for part in row[1]:

print ("Part {0}:".format(partnum))

for point in part:

print ("{0}, {1}".format(point.X, point.Y))

partnum += 1

For which types of datasets will this script work correctly? (check all that apply)

Wähle eine oder mehr der folgenden:

Single-part point features
Multi-part point features
Multi-part polygon features with holes
Multi-part polyline and polygon features
Single-part polyline and polygon features
Single-part polygon features with holes

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Frage 10 von 10

1

Consider the following script to print the coordinates of the vertices of the features of a feature class.

import arcpy

from arcpy import env

env.workspace = "C:/Data"

fc = "features.shp"

cursor = arcpy.da.SearchCursor(fc, ["OID@", "SHAPE@"])

for row in cursor:

print ("Feature {0}: ".format(row[0]))

partnum = 0

for part in row[1]:

print ("Part {0}:".format(partnum))

for point in part:

print ("{0}, {1}".format(point.X, point.Y))

partnum += 1

Line 10 of the code reads 'for part in row[1]:'. Why does the code use row[1] instead of just row?

Wähle eine der folgenden:

because you only want to obtain the first part of the geometry object
because the search cursor returns a list and row[1] obtains the geometry object
because the script is only designed to work for single part features
because the search cursor returns a list and row[1] obtains the list of coordinates
because you want to start numbering the parts of each features at 1

	Erstellt von Maggie Samson vor mehr als 5 Jahre

Geography Quiz am GEOM 73 - Python Quiz 3, erstellt von Maggie Samson am 13/04/2019.

GEOM 73 - Python Quiz 3

GEOM 73 - Python Quiz 3

Frage 1 von 10

Which cursors of the arcpy.da module can be used to work with geometry objects using SHAPE@?

Wähle eine der folgenden:

Erklärung

Frage 2 von 10

Which of the following is not a geometry token in ArcPy?

Wähle eine der folgenden:

Erklärung

Frage 3 von 10

What is the main reason to use geometry tokens instead of SHAPE@?

Wähle eine der folgenden:

Erklärung

Frage 4 von 10

When using geometry tokens in a search cursor for single part polylines and polygons, what does the search cursor return for each row in the feature attribute table?

Wähle eine der folgenden:

Erklärung

Frage 5 von 10

Wähle eine der folgenden:

Erklärung

Frage 6 von 10

Which property(ies) of a geometry objects is (are) used to determine whether a specific feature is multipart or single part?

Wähle eine oder mehr der folgenden:

Erklärung

Frage 7 von 10

Some polygon features contain 'holes'. When you work with geometry objects for such polygons, how can you determine whether these holes are present?

Wähle eine der folgenden:

Erklärung

Frage 8 von 10

Consider a scenario where you write a script to create a new polyline out of a text file with coordinates for the vertices. You will need to use a cursor object to create new geometry objects. Which of the following is the correct line of code to set up your cursor object?

Wähle eine der folgenden:

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Frage 9 von 10

Wähle eine oder mehr der folgenden:

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Frage 10 von 10

Wähle eine der folgenden:

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