🎉 static viz: population over the long run (#5602)

Author: veronikasamborska1994

dag/static_viz.yml

@@ -2,3 +2,8 @@ steps:
   # World population growth visualization
   export://static_viz/population/2026-01-26/world_population_growth:
     - data://garden/demography/2024-07-15/population
+
+  # World population long-run visualization (10,000 BCE - 2100)
+  export://static_viz/population/2026-02-02/world_population_long_run:
+    - data://grapher/demography/2024-07-15/population
+    - data://grapher/demography/2025-10-22/life_expectancy

etl/helpers.py

@@ -913,6 +913,27 @@ def create_explorer_legacy(
 
         return explorer
 
+    def export_fig(self, fig, filename: str, extensions: list[str], **kwargs) -> None:
+        """Export a matplotlib figure to multiple formats.
+
+        :param fig: The matplotlib figure to export.
+        :param filename: The base filename (without extension).
+        :param extensions: List of file extensions to export (e.g., ["png", "svg"]).
+        :param kwargs: Additional keyword arguments to pass to fig.savefig().
+        """
+        for ext in extensions:
+            path = self.directory / f"{filename}.{ext}"
+            save_kwargs = {
+                "fname": path,
+                "format": ext,
+                **kwargs,
+            }
+            if ext == "svg":
+                # Remove date metadata for SVG to keep files clean
+                save_kwargs["metadata"] = {"Date": None}
+            fig.savefig(**save_kwargs)
+            self.log.info(f"Saved chart to {path}")
+
 
 def _match_dependencies(pattern: str, dependencies: set[str]) -> set[str]:
     regex = re.compile(pattern)