Pyqgis Programmer 39s Guide 3 Pdf Work Here

# Assuming layout has a coverage layer set layout = project.layoutManager().layoutByName("AtlasLayout") exporter = QgsLayoutExporter(layout) atlas_layout = layout.atlas() atlas_layout.setEnabled(True) atlas_layout.setCoverageLayer(atlas_layer) # polygon grid, e.g., 100 map sheets Export each feature as a separate PDF page or file for i in range(atlas_layout.count()): atlas_layout.setCurrentFeature(i) # Option 1: Single multi-page PDF exporter.exportToPdf(f"C:/GIS/atlas_page_i.pdf", QgsLayoutExporter.PdfExportSettings()) Merging PDFs with PyQGIS QGIS itself does not merge PDFs, but your PyQGIS script can leverage Python’s PyPDF2 or pypdf library after export:

with open("metadatified.pdf", "wb") as f: writer.write(f) Here are three typical contracts that require a deep understanding of the PyQGIS 3 PDF workflow: 1. Batch PDF Generation from a Template Scenario: A city planning department has 50 district maps. Each PDF must show the same legend, title block, and scale bar, but with a different map extent and a district-specific label. pyqgis programmer 39s guide 3 pdf work

from pypdf import PdfReader, PdfWriter reader = PdfReader("original.pdf") writer = PdfWriter() writer.append_pages_from_reader(reader) metadata = "/Title": "PyQGIS Automated Map", "/Author": "GIS Programmer", "/Subject": "Land Use Analysis", "/Keywords": "QGIS, PyQGIS, Automation" # Assuming layout has a coverage layer set layout = project

# pyqgis_pdf_toolkit.py class QgsPdfAutomator: def __init__(self, project_path, layout_name): self.project = QgsProject.instance() self.project.read(project_path) self.layout = self.project.layoutManager().layoutByName(layout_name) self.exporter = QgsLayoutExporter(self.layout) def update_map_extent(self, layer_name, filter_expr): # ... from pypdf import PdfReader

district_layer = QgsProject.instance().mapLayersByName("districts")[0] for feature in district_layer.getFeatures(): # Set map extent to feature geometry map_item.zoomToExtent(feature.geometry().boundingBox()) # Update a text label with district name title_label.setText(f"District feature['name']") # Refresh layout layout.refresh() exporter.exportToPdf(f"feature['name'].pdf", settings) Scenario: You need a PDF where clicking a feature on a legend or table opens a bookmarked page.