Merge branch 'master' of https://github.com/dexplo/dataframe_image

Author: PaleNeutron

dataframe_image/_matplotlib_table.py

@@ -14,7 +14,7 @@
 
 class TableMaker:
     def __init__(
-        self, fontsize=14, encode_base64=True, limit_crop=True, for_document=True
+        self, fontsize=14, encode_base64=True, limit_crop=True, for_document=True, savefig_dpi=None
     ):
         self.original_fontsize = fontsize
         self.encode_base64 = encode_base64
@@ -28,6 +28,7 @@ def __init__(
             self.figheight = 4
             self.wrap_length = 10
         self.dpi = 100
+        self.savefig_dpi = savefig_dpi
 
     def parse_html(self, html):
         html = html.replace("<br>", "\n")
@@ -249,7 +250,7 @@ def print_table(self):
         end = self.figwidth - start
         bbox = Bbox([[start - 0.1, y * h], [end + 0.1, h]])
         buffer = io.BytesIO()
-        self.fig.savefig(buffer, bbox_inches=bbox)
+        self.fig.savefig(buffer, bbox_inches=bbox, dpi=self.savefig_dpi)
         img_str = buffer.getvalue()
         if self.encode_base64:
             img_str = base64.b64encode(img_str).decode()

dataframe_image/_pandas_accessor.py

@@ -21,6 +21,7 @@ def export(
         max_cols=None,
         table_conversion="chrome",
         chrome_path=None,
+        dpi=None
     ):
         return _export(
             self._df,
@@ -30,6 +31,7 @@ def export(
             max_cols,
             table_conversion,
             chrome_path,
+            dpi
         )
 
 
@@ -41,13 +43,14 @@ def export(
     max_cols=None,
     table_conversion="chrome",
     chrome_path=None,
+    dpi=None
 ):
     return _export(
-        obj, filename, fontsize, max_rows, max_cols, table_conversion, chrome_path
-    )
+        obj, filename, fontsize, max_rows, max_cols, table_conversion, chrome_path, dpi
+   )
 
 
-def _export(obj, filename, fontsize, max_rows, max_cols, table_conversion, chrome_path):
+def _export(obj, filename, fontsize, max_rows, max_cols, table_conversion, chrome_path, dpi):
     is_styler = isinstance(obj, Styler)
     df = obj.data if is_styler else obj
 
@@ -59,12 +62,13 @@ def _export(obj, filename, fontsize, max_rows, max_cols, table_conversion, chrom
             fontsize=fontsize,
             encode_base64=False,
             limit_crop=False,
+            device_scale_factor=(1 if dpi == None else dpi/100.0)
         ).run
     else:
         from ._matplotlib_table import TableMaker
 
         converter = TableMaker(
-            fontsize=fontsize, encode_base64=False, for_document=False
+            fontsize=fontsize, encode_base64=False, for_document=False, savefig_dpi=dpi
         ).run
 
     if df.shape[0] > MAX_ROWS and max_rows is None:
@@ -166,6 +170,15 @@ def _export(obj, filename, fontsize, max_rows, max_cols, table_conversion, chrom
     Path to your machine's chrome executable. When `None`, it is 
     automatically found. Use this when chrome is not automatically found.
 
+dpi : int, default `None`
+    Dots per inch - Use this to change the resolution ("quality") of the image.
+    
+    If `table_conversion`=`matplotlib`, this value is directly passed to 
+    the "savefig" method. When `None`, the figure's DPI is used.
+     
+    If `table_conversion`=`chrome`, the dpi value is converted to a 
+    "device scale factor" but should provide the same effect. When `None`,
+    the "device scale factor" is 1.
 """
 
 export_intro = """

dataframe_image/_screenshot.py

@@ -83,6 +83,7 @@ def __init__(
         fontsize=18,
         encode_base64=True,
         limit_crop=True,
+        device_scale_factor=1
     ):
         self.center_df = center_df
         self.max_rows = max_rows
@@ -93,6 +94,7 @@ def __init__(
         self.css = self.get_css(fontsize)
         self.encode_base64 = encode_base64
         self.limit_crop = limit_crop
+        self.device_scale_factor = device_scale_factor
 
     def get_css(self, fontsize):
         mod_dir = Path(__file__).resolve().parent
@@ -117,6 +119,7 @@ def take_screenshot(self):
                 "--headless",
                 "--no-sandbox",
                 "--crash-dumps-dir=/tmp",
+                f"--force-device-scale-factor={self.device_scale_factor}",
             ]
 
             if self.ss_width and self.ss_height:

tests/dfi-dpi-change-check.xlsx

@@ -7,17 +7,34 @@
     "tests/notebooks/data/covid19.csv", parse_dates=["date"], index_col="date"
 )
 
+test_dpi_values = [50, 400, 600, 800]
 
 class TestImage:
     def test_df(self):
         df.tail(10).dfi.export("tests/test_output/covid19.png")
 
+    @pytest.mark.parametrize('dpi', test_dpi_values)
+    def test_chrome_changed_dpi(self, dpi):
+        df.tail(10).dfi.export(f"tests/test_output/covid19_dpi_{dpi}.png", dpi=dpi)
+
     def test_styled(self):
         df.tail(10).style.background_gradient().export_png(
             "tests/test_output/covid19_styled.png"
         )
 
+    @pytest.mark.parametrize('dpi', test_dpi_values)
+    def test_styled_changed_dpi(self, dpi):
+        df.tail(10).style.background_gradient().export_png(
+            f"tests/test_output/covid19_styled_dpi_{dpi}.png", dpi=dpi
+        )
+
     def test_mpl(self):
         df.tail(10).dfi.export(
             "tests/test_output/covid19_mpl.png", table_conversion="matplotlib"
         )
+
+    @pytest.mark.parametrize('dpi', test_dpi_values)
+    def test_mpl_changed_dpi(self, dpi):
+        df.tail(10).dfi.export(
+            f"tests/test_output/covid19_mpl_dpi_{dpi}.png",
+            table_conversion="matplotlib", dpi=dpi)