chore: separate python modules

data_platform/helpers/__init__.py

@@ -0,0 +1,65 @@
+"""Shared helper utilities for Dagster assets."""
+
+import json
+
+
+def safe(val):
+    """Convert non-serialisable values (tuples, lists of dicts, etc.) for JSONB."""
+    if isinstance(val, list | dict | tuple):
+        return json.dumps(val, default=str)
+    return val
+
+
+def safe_int(val):
+    """Try to cast to int, return None on failure."""
+    if val is None:
+        return None
+    try:
+        return int(val)
+    except (ValueError, TypeError):
+        try:
+            return int(float(val))
+        except (ValueError, TypeError):
+            return None
+
+
+def md_preview_table(
+    rows: list[dict],
+    columns: list[tuple[str, str]],
+    formatters: dict[str, callable] | None = None,
+) -> str:
+    """Build a markdown table from a list of row dicts.
+
+    Args:
+        rows: List of dictionaries containing row data.
+        columns: List of (key, header_label) tuples defining the columns.
+        formatters: Optional dict mapping column keys to formatting callables.
+            Each callable receives the raw value and returns a display string.
+            Columns without a formatter fall back to the raw value or "–".
+    """
+    formatters = formatters or {}
+    headers = [label for _, label in columns]
+    lines = [
+        "| " + " | ".join(headers) + " |",
+        "| " + " | ".join("---" for _ in headers) + " |",
+    ]
+    for r in rows:
+        cells = []
+        for key, _ in columns:
+            val = r.get(key)
+            if key in formatters:
+                cells.append(formatters[key](val))
+            else:
+                cells.append(str(val) if val is not None else "–")
+        lines.append("| " + " | ".join(cells) + " |")
+    return "\n".join(lines)
+
+
+def format_euro(val) -> str:
+    """Format an integer as €-prefixed with thousands separators, or '–'."""
+    return f"€{val:,}" if val else "–"
+
+
+def format_area(val) -> str:
+    """Format an integer as m² area, or '–'."""
+    return f"{val} m²" if val else "–"