本文整理汇总了Python中qgis.core.QgsFeatureRequest.setLimit方法的典型用法代码示例。如果您正苦于以下问题：Python QgsFeatureRequest.setLimit方法的具体用法？Python QgsFeatureRequest.setLimit怎么用？Python QgsFeatureRequest.setLimit使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsFeatureRequest的用法示例。
在下文中一共展示了QgsFeatureRequest.setLimit方法的3个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: print_attribute_table
# 需要导入模块: from qgis.core import QgsFeatureRequest [as 别名]
# 或者: from qgis.core.QgsFeatureRequest import setLimit [as 别名]
def print_attribute_table(layer, limit=-1):
"""Print the attribute table in the console.
:param layer: The layer to print.
:type layer: QgsVectorLayer
:param limit: The limit in the query.
:type limit: integer
"""
if layer.wkbType() == QGis.WKBNoGeometry:
geometry = False
else:
geometry = True
headers = []
if geometry:
headers.append('geom')
headers.extend(
[f.name() + ' : ' + str(f.type()) for f in layer.fields().toList()])
request = QgsFeatureRequest()
request.setLimit(limit)
data = []
for feature in layer.getFeatures(request):
attributes = []
if geometry:
attributes.append(feature.geometry().type())
attributes.extend(feature.attributes())
data.append(attributes)
print pretty_table(data, headers)示例2: runGetFeatureTests
# 需要导入模块: from qgis.core import QgsFeatureRequest [as 别名]
# 或者: from qgis.core.QgsFeatureRequest import setLimit [as 别名]
def runGetFeatureTests(self, provider):
assert len([f for f in provider.getFeatures()]) == 5
self.assert_query(provider, 'name ILIKE \'QGIS\'', [])
self.assert_query(provider, '"name" IS NULL', [5])
self.assert_query(provider, '"name" IS NOT NULL', [1, 2, 3, 4])
self.assert_query(provider, '"name" NOT LIKE \'Ap%\'', [1, 3, 4])
self.assert_query(provider, '"name" NOT ILIKE \'QGIS\'', [1, 2, 3, 4])
self.assert_query(provider, '"name" NOT ILIKE \'pEAR\'', [1, 2, 4])
self.assert_query(provider, 'name = \'Apple\'', [2])
self.assert_query(provider, 'name <> \'Apple\'', [1, 3, 4])
self.assert_query(provider, 'name = \'apple\'', [])
self.assert_query(provider, '"name" <> \'apple\'', [1, 2, 3, 4])
self.assert_query(provider, '(name = \'Apple\') is not null', [1, 2, 3, 4])
self.assert_query(provider, 'name LIKE \'Apple\'', [2])
self.assert_query(provider, 'name LIKE \'aPple\'', [])
self.assert_query(provider, 'name ILIKE \'aPple\'', [2])
self.assert_query(provider, 'name ILIKE \'%pp%\'', [2])
self.assert_query(provider, 'cnt > 0', [1, 2, 3, 4])
self.assert_query(provider, '-cnt > 0', [5])
self.assert_query(provider, 'cnt < 0', [5])
self.assert_query(provider, '-cnt < 0', [1, 2, 3, 4])
self.assert_query(provider, 'cnt >= 100', [1, 2, 3, 4])
self.assert_query(provider, 'cnt <= 100', [1, 5])
self.assert_query(provider, 'pk IN (1, 2, 4, 8)', [1, 2, 4])
self.assert_query(provider, 'cnt = 50 * 2', [1])
self.assert_query(provider, 'cnt = 99 + 1', [1])
self.assert_query(provider, 'cnt = 101 - 1', [1])
self.assert_query(provider, 'cnt - 1 = 99', [1])
self.assert_query(provider, '-cnt - 1 = -101', [1])
self.assert_query(provider, '-(-cnt) = 100', [1])
self.assert_query(provider, '-(cnt) = -(100)', [1])
self.assert_query(provider, 'cnt + 1 = 101', [1])
self.assert_query(provider, 'cnt = 1100 % 1000', [1])
self.assert_query(provider, '"name" || \' \' || "name" = \'Orange Orange\'', [1])
self.assert_query(provider, '"name" || \' \' || "cnt" = \'Orange 100\'', [1])
self.assert_query(provider, '\'x\' || "name" IS NOT NULL', [1, 2, 3, 4])
self.assert_query(provider, '\'x\' || "name" IS NULL', [5])
self.assert_query(provider, 'cnt = 10 ^ 2', [1])
self.assert_query(provider, '"name" ~ \'[OP]ra[gne]+\'', [1])
self.assert_query(provider, '"name"="name2"', [2, 4]) # mix of matched and non-matched case sensitive names
self.assert_query(provider, 'true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'false', [])
# Three value logic
self.assert_query(provider, 'false and false', [])
self.assert_query(provider, 'false and true', [])
self.assert_query(provider, 'false and NULL', [])
self.assert_query(provider, 'true and false', [])
self.assert_query(provider, 'true and true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true and NULL', [])
self.assert_query(provider, 'NULL and false', [])
self.assert_query(provider, 'NULL and true', [])
self.assert_query(provider, 'NULL and NULL', [])
self.assert_query(provider, 'false or false', [])
self.assert_query(provider, 'false or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'false or NULL', [])
self.assert_query(provider, 'true or false', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true or NULL', [1, 2, 3, 4, 5])
self.assert_query(provider, 'NULL or false', [])
self.assert_query(provider, 'NULL or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'NULL or NULL', [])
self.assert_query(provider, 'not true', [])
self.assert_query(provider, 'not false', [1, 2, 3, 4, 5])
self.assert_query(provider, 'not null', [])
# not
self.assert_query(provider, 'not name = \'Apple\'', [1, 3, 4])
self.assert_query(provider, 'not name IS NULL', [1, 2, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' or name = \'Apple\'', [1, 2, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' or not name = \'Apple\'', [1, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' and pk = 4', [4])
self.assert_query(provider, 'not name = \'Apple\' and not pk = 4', [1, 3])
self.assert_query(provider, 'not pk IN (1, 2, 4, 8)', [3, 5])
# type conversion - QGIS expressions do not mind that we are comparing a string
# against numeric literals
self.assert_query(provider, 'num_char IN (2, 4, 5)', [2, 4, 5])
# geometry
self.assert_query(provider, 'intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [1, 2])
# combination of an uncompilable expression and limit
feature = next(self.vl.getFeatures('pk=4'))
context = QgsExpressionContext()
scope = QgsExpressionContextScope()
scope.setVariable('parent', feature)
context.appendScope(scope)
request = QgsFeatureRequest()
request.setExpressionContext(context)
request.setFilterExpression('"pk" = attribute(@parent, \'pk\')')
request.setLimit(1)
values = [f['pk'] for f in self.vl.getFeatures(request)]
self.assertEqual(values, [4])示例3: runGetFeatureTests
# 需要导入模块: from qgis.core import QgsFeatureRequest [as 别名]
# 或者: from qgis.core.QgsFeatureRequest import setLimit [as 别名]
#.........这里部分代码省略.........
self.assert_query(provider, 'false', [])
# Three value logic
self.assert_query(provider, 'false and false', [])
self.assert_query(provider, 'false and true', [])
self.assert_query(provider, 'false and NULL', [])
self.assert_query(provider, 'true and false', [])
self.assert_query(provider, 'true and true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true and NULL', [])
self.assert_query(provider, 'NULL and false', [])
self.assert_query(provider, 'NULL and true', [])
self.assert_query(provider, 'NULL and NULL', [])
self.assert_query(provider, 'false or false', [])
self.assert_query(provider, 'false or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'false or NULL', [])
self.assert_query(provider, 'true or false', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'true or NULL', [1, 2, 3, 4, 5])
self.assert_query(provider, 'NULL or false', [])
self.assert_query(provider, 'NULL or true', [1, 2, 3, 4, 5])
self.assert_query(provider, 'NULL or NULL', [])
self.assert_query(provider, 'not true', [])
self.assert_query(provider, 'not false', [1, 2, 3, 4, 5])
self.assert_query(provider, 'not null', [])
# not
self.assert_query(provider, 'not name = \'Apple\'', [1, 3, 4])
self.assert_query(provider, 'not name IS NULL', [1, 2, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' or name = \'Apple\'', [1, 2, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' or not name = \'Apple\'', [1, 3, 4])
self.assert_query(provider, 'not name = \'Apple\' and pk = 4', [4])
self.assert_query(provider, 'not name = \'Apple\' and not pk = 4', [1, 3])
self.assert_query(provider, 'not pk IN (1, 2, 4, 8)', [3, 5])
# type conversion - QGIS expressions do not mind that we are comparing a string
# against numeric literals
self.assert_query(provider, 'num_char IN (2, 4, 5)', [2, 4, 5])
#function
self.assert_query(provider, 'sqrt(pk) >= 2', [4, 5])
self.assert_query(provider, 'radians(cnt) < 2', [1, 5])
self.assert_query(provider, 'degrees(pk) <= 200', [1, 2, 3])
self.assert_query(provider, 'abs(cnt) <= 200', [1, 2, 5])
self.assert_query(provider, 'cos(pk) < 0', [2, 3, 4])
self.assert_query(provider, 'sin(pk) < 0', [4, 5])
self.assert_query(provider, 'tan(pk) < 0', [2, 3, 5])
self.assert_query(provider, 'acos(-1) < pk', [4, 5])
self.assert_query(provider, 'asin(1) < pk', [2, 3, 4, 5])
self.assert_query(provider, 'atan(3.14) < pk', [2, 3, 4, 5])
self.assert_query(provider, 'atan2(3.14, pk) < 1', [3, 4, 5])
self.assert_query(provider, 'exp(pk) < 10', [1, 2])
self.assert_query(provider, 'ln(pk) <= 1', [1, 2])
self.assert_query(provider, 'log(3, pk) <= 1', [1, 2, 3])
self.assert_query(provider, 'log10(pk) < 0.5', [1, 2, 3])
self.assert_query(provider, 'round(3.14) <= pk', [3, 4, 5])
self.assert_query(provider, 'round(0.314,1) * 10 = pk', [3])
self.assert_query(provider, 'floor(3.14) <= pk', [3, 4, 5])
self.assert_query(provider, 'ceil(3.14) <= pk', [4, 5])
self.assert_query(provider, 'pk < pi()', [1, 2, 3])
self.assert_query(provider, 'round(cnt / 66.67) <= 2', [1, 5])
self.assert_query(provider, 'floor(cnt / 66.67) <= 2', [1, 2, 5])
self.assert_query(provider, 'ceil(cnt / 66.67) <= 2', [1, 5])
self.assert_query(provider, 'pk < pi() / 2', [1])
self.assert_query(provider, 'pk = char(51)', [3])
self.assert_query(provider, 'pk = coalesce(NULL,3,4)', [3])
self.assert_query(provider, 'lower(name) = \'apple\'', [2])
self.assert_query(provider, 'upper(name) = \'APPLE\'', [2])
self.assert_query(provider, 'name = trim(\' Apple \')', [2])
# geometry
# azimuth and touches tests are deactivated because they do not pass for WFS provider
#self.assert_query(provider, 'azimuth($geometry,geom_from_wkt( \'Point (-70 70)\')) < pi()', [1, 5])
self.assert_query(provider, 'x($geometry) < -70', [1, 5])
self.assert_query(provider, 'y($geometry) > 70', [2, 4, 5])
self.assert_query(provider, 'xmin($geometry) < -70', [1, 5])
self.assert_query(provider, 'ymin($geometry) > 70', [2, 4, 5])
self.assert_query(provider, 'xmax($geometry) < -70', [1, 5])
self.assert_query(provider, 'ymax($geometry) > 70', [2, 4, 5])
self.assert_query(provider, 'disjoint($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [4, 5])
self.assert_query(provider, 'intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))', [1, 2])
#self.assert_query(provider, 'touches($geometry,geom_from_wkt( \'Polygon ((-70.332 66.33, -65.32 66.33, -65.32 78.3, -70.332 78.3, -70.332 66.33))\'))', [1, 4])
self.assert_query(provider, 'contains(geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'),$geometry)', [1, 2])
self.assert_query(provider, 'distance($geometry,geom_from_wkt( \'Point (-70 70)\')) > 7', [4, 5])
self.assert_query(provider, 'intersects($geometry,geom_from_gml( \'<gml:Polygon srsName="EPSG:4326"><gml:outerBoundaryIs><gml:LinearRing><gml:coordinates>-72.2,66.1 -65.2,66.1 -65.2,72.0 -72.2,72.0 -72.2,66.1</gml:coordinates></gml:LinearRing></gml:outerBoundaryIs></gml:Polygon>\'))', [1, 2])
# combination of an uncompilable expression and limit
feature = next(self.vl.getFeatures('pk=4'))
context = QgsExpressionContext()
scope = QgsExpressionContextScope()
scope.setVariable('parent', feature)
context.appendScope(scope)
request = QgsFeatureRequest()
request.setExpressionContext(context)
request.setFilterExpression('"pk" = attribute(@parent, \'pk\')')
request.setLimit(1)
values = [f['pk'] for f in self.vl.getFeatures(request)]
self.assertEqual(values, [4])