Identify Sphinx gallery cell header with a regexp

jupytext/cell_reader.py

@@ -471,7 +471,7 @@ class SphinxGalleryScriptCellReader(ScriptCellReader):
 
     comment = '#'
     default_language = 'python'
-    twenty_hash = '#' * 20
+    twenty_hash = re.compile('^#( |)#{19,}\s*$')
     markdown_marker = None
     rst2md = False
 
@@ -486,7 +486,7 @@ def start_of_new_markdown_cell(self, line):
             if line.startswith(triple_quote):
                 return triple_quote
 
-        if line.startswith('#') and self.twenty_hash in line:
+        if self.twenty_hash.match(line):
             return line
 
         return None
@@ -576,7 +576,7 @@ def find_cell_content(self, lines):
                     last = lines[cell_end_marker - 1]
                     lines[cell_end_marker - 1] = \
                         last[:last.rfind(self.markdown_marker)]
-            if self.markdown_marker.startswith(self.twenty_hash):
+            if self.twenty_hash.match(self.markdown_marker):
                 cell_start = 1
         else:
             self.metadata = {}

tests/test_read_simple_sphinx.py

@@ -69,6 +69,9 @@ def test_read_more_complex_file(script="""'''This is a markdown cell'''
 Another markdown cell'''
 1 + 2 + 3 + 4
 
+# ################################
+# A fifth one
+
 '''And a last one
 '''
 """):
@@ -97,6 +100,9 @@ def test_read_more_complex_file(script="""'''This is a markdown cell'''
     assert nb.cells[6].source == '1 + 2 + 3 + 4'
 
     assert nb.cells[7].cell_type == 'markdown'
-    assert nb.cells[7].source == 'And a last one'
+    assert nb.cells[7].source == 'A fifth one'
+
+    assert nb.cells[8].cell_type == 'markdown'
+    assert nb.cells[8].source == 'And a last one'
 
-    assert len(nb.cells) == 8
+    assert len(nb.cells) == 9