Merge pull request #6 from dataiku/feature/dss12-sc-181423-multi-sheet-excel-export-apply-a-formatting

Feature/dss12 sc 181423 multi sheet excel export apply a formatting

Author: Ellana42

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## [Version 1.1.2](https://github.com/dataiku/dss-plugin-multisheet-excel-export/releases/tag/v1.1.2) - Feature release - 2024-05
+- Style exported worksheet header
+- Auto-size columns to fit header
+
 ## [Version 1.1.1](https://github.com/dataiku/dss-plugin-multisheet-excel-export/releases/tag/v1.1.0) - Chore release - 2023-08
 - Use python library to create temp file instead of a custom cache
 

plugin.json

@@ -1,6 +1,6 @@
 {
     "id" : "multisheet-excel-export",
-    "version" : "1.1.1",
+    "version" : "1.1.2",
 
 
     "meta" : {

python-lib/xlsx_writer.py

@@ -7,11 +7,102 @@
 """
 
 import logging
+import math
+from typing import Tuple
+
+from openpyxl.styles import Alignment, Font, PatternFill, Side
+from openpyxl.styles.borders import Border
+from openpyxl.styles.colors import WHITE
+from openpyxl.utils import get_column_letter
+from openpyxl.worksheet.dimensions import ColumnDimension, DimensionHolder
+from openpyxl.worksheet.worksheet import Worksheet
 import pandas as pd
 
+DATAIKU_TEAL = "FF2AB1AC"
+LETTER_WIDTH = 1.20 # Approximative letter width to scale column width
+MAX_LENGTH_TO_SHOW = 45 # Limit copied from DSS native excel exporter
+
 logger = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO, format='Multi-Sheet Excel Exporter | %(levelname)s - %(message)s')
 
+def style_header(worksheet: Worksheet, 
+                  font_name: str = "Calibri", 
+                  font_size: int = 11, 
+                  font_color : str = WHITE, 
+                  background_color : str = DATAIKU_TEAL,
+                  bold : bool = True
+                 ):
+    """
+    Style header of the worksheet
+    """
+
+    if worksheet.min_column < 1:
+        logger.warn(f"No header row for worksheet {worksheet}. Styling skipped.")
+        return
+
+    font = Font(name=font_name, size=font_size, color=font_color, bold=bold)
+    fill = PatternFill("solid", fgColor=background_color)
+
+    no_border_side = Side(border_style=None)
+    border = Border(left=no_border_side, right=no_border_side, top=no_border_side, bottom=no_border_side)
+
+    alignment = Alignment(vertical='bottom', horizontal='center')
+
+    for header_cell in worksheet[1]:
+        header_cell.font = font
+        header_cell.fill = fill
+        header_cell.border = border
+        header_cell.alignment = alignment
+
+def get_column_width(column: Tuple):
+    """
+    Find optimum column width based on content and header length
+    Based on the computations of DSS native excel output formatter
+    """
+
+    header = column[0]
+    length_header = len(str(header.value))
+
+    sum_length_cells = 0
+    max_length_cells = 0
+    for cell in column:
+        length_cell = len(str(cell.value))
+        max_length_cells = max(max_length_cells, length_cell)
+        sum_length_cells += length_cell
+
+    # Computations from ExcelOutputFormatter.java ExcelOutputFormatter.footer
+    average_length_cell = math.ceil(sum_length_cells / (len(column) + 1))
+    max_length_cells = min(max_length_cells, MAX_LENGTH_TO_SHOW)
+    
+    if max_length_cells > 2 * average_length_cell: # if max length much bigger than average
+        length_to_show = int((max_length_cells + average_length_cell) / 2)
+    else:
+        length_to_show = max_length_cells
+
+    length_to_show = max(length_to_show, length_header) 
+
+    return length_to_show * LETTER_WIDTH
+
+def auto_size_column_width(worksheet: Worksheet):
+    """
+    Resize columns based on the length of the header text
+    """
+    if worksheet.min_column < 1:
+        logger.warn(f"No header row for worksheet {worksheet}. Column auto-size skipped.")
+        return
+
+    dimension_holder = DimensionHolder(worksheet=worksheet) 
+
+    column_indexes = range(worksheet.min_column, worksheet.max_column + 1)
+    for index_column, column in zip(column_indexes, worksheet.iter_cols()):
+
+        column_width = get_column_width(column)
+        dimension_holder[get_column_letter(index_column)] = ColumnDimension(worksheet, 
+                                                           min=index_column, 
+                                                           max=index_column,
+                                                           width=column_width)
+    worksheet.column_dimensions = dimension_holder
+
 
 def dataframes_to_xlsx(input_dataframes_names, xlsx_abs_path, dataframe_provider):
     """
@@ -22,10 +113,24 @@ def dataframes_to_xlsx(input_dataframes_names, xlsx_abs_path, dataframe_provider
     """
     logger.info("Writing output xlsx file ...")
     writer = pd.ExcelWriter(xlsx_abs_path, engine='openpyxl')
+
     for name in input_dataframes_names:
         df = dataframe_provider(name)
+
         logger.info("Writing dataset into excel sheet...")
         df.to_excel(writer, sheet_name=name, index=False, encoding='utf-8')
+
+        worksheet = writer.sheets.get(name)
+
+        if worksheet is None:
+            logger.warn(f"No worksheet for dataset {name}. Written but styling skipped.")
+            continue
+
+        logger.info(f"Styling excel sheet...")
+        style_header(worksheet)
+        auto_size_column_width(worksheet)
+
         logger.info("Finished writing dataset {} into excel sheet.".format(name))
+
     writer.save()
     logger.info("Done writing output xlsx file")