qgis_map_maker.py

# NOTE: There's a post that will be on siliconcreek.net about this someday soon.

import os

map_list = [
{'fieldname': 'final_accessibility_auPkRetail', 'Legend Name': 'Peak Auto Accessibility to Retail', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_auPkTotal', 'Legend Name': 'Peak Auto Accessibility to Total Emp.', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_auOpRetail', 'Legend Name': 'Off-Peak Auto Accessibility to Retail', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_auOpTotal', 'Legend Name': 'Off-Peak Auto Accessibility to Total Emp.', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_trPkRetail', 'Legend Name': 'Peak Transit Accessibility to Retail', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_trPkTotal', 'Legend Name': 'Peak Transit Accessibility to Total Emp', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_trPkHH', 'Legend Name': 'Peak Transit Accessibility to Households', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_trOpRetail', 'Legend Name': 'Off-Peak Transit Accessibility to Retail', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_trOpTotal', 'Legend Name': 'Off-Peak Transit Accessibility to Total Emp.', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_nmRetail', 'Legend Name': 'Non-motorized Accessibility to Retail', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'final_accessibility_nmTotal', 'Legend Name': 'Non-motorized Accessibility to Total Emp', 'qryZero': False, 'tablename': 'final_accessibility', 'precision': 4},
{'fieldname': 'land_use_HH', 'Legend Name': 'Number of Households', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_GQPOP', 'Legend Name': 'Group Quarters Population', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_TOTEMP', 'Legend Name': 'Total Employment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_INDEMP', 'Legend Name': 'Industrial Employment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_RETEMP', 'Legend Name': 'Retail Employment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_OFFEMP', 'Legend Name': 'Office Employment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_OTHEMP', 'Legend Name': 'Other Employment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_K_8', 'Legend Name': 'Primary School Enrollment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_G9_12', 'Legend Name': 'High School Student Enrollment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0},
{'fieldname': 'land_use_COLLEGE', 'Legend Name': 'College Enrollment', 'qryZero': True, 'tablename': 'land_use', 'precision': 0}]
{'fieldname': 'land_use_AREATYPE', 'Legend Name': 'Area Type', 'qryZero': True, 'tablename': 'land_use', 'or_classes': 6, 'cat_legend': True, 'precision': 0}
{'fieldname': 'final_land_use_density_index', 'Legend Name': 'Density Index', 'qryZero': False, 'tablename': 'final_land_use', 'precision': 4}
]

export_map_location = "C:\\MAKE\\A\\PATH\\HERE"

extents = [xmin, ymin, xmax, ymax]

cb_colors = ['#8dd3c7','#ffffb3','#bebada','#fb8072','#80b1d3','#fdb462','#b3de69','#fccde5','#d9d9d9','#bc80bd','#ccebc5','#ffed6f']

layer_list = QgsProject.instance().mapLayers().values()
for layer in layer_list:
    if layer.source().find("TAZ_FILE_NAME_PART_THAT_IS_UNIQUE") > 0:
        break
layer.setSubsetString("")

for map in map_list:
    fieldname = map['fieldname']
    print(f"Building {fieldname}")
    query = map['qryZero']
    table_name = map['tablename']
    target_query = ""
    legend_name = map['Legend Name']
    num_classes = 10
    if 'or_classes' in map.keys():
        num_classes = map['or_classes']
    categorical = False
    if 'cat_legend' in map.keys():
        categorical = map['categorical']
    precision = 0
    if 'precision' in map.keys():
        precision = map['precision']
    if query:
        layer_join = layer.vectorJoins()
        for joined_layer_name in layer_join:
            if joined_layer_name.joinLayer().name() == table_name:
                joined_layer = joined_layer_name.joinLayer()
                key_field = joined_layer_name.joinFieldName()
                select_tazs = f"Select {key_field} from {joined_layer} where {fieldname} > 0"
                expected_fields = [key_field]
                request = QgsFeatureRequest()
                request.setFlags(QgsFeatureRequest.NoGeometry)
                taz_list_feat_iter = list(joined_layer.getFeatures(request))
                target_query = f"\"{joined_layer_name.targetFieldName()}\" in ("
                for taz_feat in taz_list_feat_iter:
                    if taz_feat.attribute(fieldname[len(table_name) + 1:]) > 0:
                        target_query += str(taz_feat.attribute(key_field)) + ","
                target_query = target_query[:-1] + ")"
                break
        layer.setSubsetString(target_query)

    format = QgsRendererRangeLabelFormat()
    format.setFormat("%1 - %2")
    format.setPrecision(precision)
    format.setTrimTrailingZeroes(True)
    if not categorical:
        groupRenderer = QgsGraduatedSymbolRenderer()
        groupRenderer.setClassAttribute(fieldname)
        groupRenderer.setClassificationMethod(QgsClassificationJenks())
        groupRenderer.setSourceColorRamp(QgsStyle().defaultStyle().colorRamp('Spectral'))
        groupRenderer.updateColorRamp(QgsStyle().defaultStyle().colorRamp('Spectral'))
        groupRenderer.setLabelFormat(format)
        groupRenderer.updateClasses(layer, num_classes)

        layer.setRenderer(groupRenderer)
        layer.setOpacity(0.4)
        layer.setName(legend_name)
        layer.triggerRepaint()
    else:
        fni = layer.fields().indexFromName(fieldname)
        unique_values = list(layer.uniqueValues(fni))
        # fill categories
        categories = []
        for unique_value in unique_values:
            # initialize the default symbol for this geometry type
            symbol = QgsSymbol.defaultSymbol(layer.geometryType())

            # configure a symbol layer
            layer_style = {}
            layer_style['color'] = cb_colors[unique_values.index(unique_value)]
            layer_style['outline'] = '#000000'
            symbol_layer = QgsSimpleFillSymbolLayer.create(layer_style)

            # replace default symbol layer with the configured one
            if symbol_layer is not None:
                symbol.changeSymbolLayer(0, symbol_layer)

            # create renderer object
            category = QgsRendererCategory(unique_value, symbol, str(unique_value))
            # entry for the list of category items
            categories.append(category)

        # create renderer object
        renderer = QgsCategorizedSymbolRenderer(fieldname, categories)

        # assign the created renderer to the layer
        if renderer is not None:
            layer.setRenderer(renderer)
        layer.setOpacity(0.4)
        layer.setName(legend_name)
        layer.triggerRepaint()

    projectLayoutManager = QgsProject.instance().layoutManager()
    layout = projectLayoutManager.layoutByName('Landscape')
    refmap = layout.referenceMap()
    bb = QgsRectangle(extents[0], extents[1], extents[2], extents[3])
    refmap.setExtent(bb)

    layout.update()
        
    exporter = QgsLayoutExporter(layout)
    export_settings = QgsLayoutExporter.ImageExportSettings()
    export_settings.cropToContents = False
    export_settings.dpi = 300
    exporter.exportToImage(os.path.join(export_map_location,fieldname + '.png'), export_settings)