new-feature: support using "$" as math quote

md2zhihu/__init__.py

@@ -455,7 +455,7 @@ def join_math_block(nodes):
     join_math_text(nodes)
 
 
-def parse_math(nodes):
+def parse_math(conf, nodes):
     """
     Extract all math segment such as ``$$ ... $$`` from a text and build a
     math_block or math_inline node.
@@ -466,10 +466,10 @@ def parse_math(nodes):
     for n in nodes:
 
         if 'children' in n:
-            n['children'] = parse_math(n['children'])
+            n['children'] = parse_math(conf, n['children'])
 
         if n['type'] == 'text':
-            new_children = extract_math(n)
+            new_children = extract_math(conf, n)
             children.extend(new_children)
         else:
             children.append(n)
@@ -502,22 +502,24 @@ def join_math_text(nodes):
             i += 1
 
 
-inline_math = r'\$\$(.*?)\$\$'
-
-
-def extract_math(n):
+def extract_math(conf, n):
     """
-    Extract ``$$ ... $$`` from a text node and build a new node.
+    Extract ``$$ ... $$`` or ``$ .. $` from a text node and build a new node.
     The original text node is split into multiple segments.
+
+    The math is a block if it is a paragraph.
+    Otherwise, it is an inline math.
     """
     children = []
 
+    math_regex = r'([$]|[$][$])([^$].*?)\1'
+
     t = n['text']
     while True:
-        match = re.search(inline_math, t, flags=re.DOTALL)
+        match = re.search(math_regex, t, flags=re.DOTALL)
         if match:
             children.append({'type': 'text', 'text': t[:match.start()]})
-            children.append({'type': 'math_inline', 'text': match.groups()[0]})
+            children.append({'type': 'math_inline', 'text': match.groups()[1]})
             t = t[match.end():]
 
             left = children[-2]['text']
@@ -1148,14 +1150,14 @@ def convert_md(conf, handler=None):
     used_refs = replace_ref_with_def(ast, refs)
 
     # extract already inlined math
-    ast = parse_math(ast)
+    ast = parse_math(conf, ast)
 
     #  with open('after-math-1', 'w') as f:
     #      f.write(pprint.pformat(ast))
 
     # join cross paragraph math
     join_math_block(ast)
-    ast = parse_math(ast)
+    ast = parse_math(conf, ast)
 
     #  with open('after-math-2', 'w') as f:
     #  f.write(pprint.pformat(ast))

test.sh

@@ -9,4 +9,4 @@ python setup.py install
 )
 
 # PYTHONPATH="$(cd ..; pwd)" pytest -x -v
-PYTHONPATH="$(cd ..; pwd)" pytest -x -v -k test_minimal_mistake
+PYTHONPATH="$(cd ..; pwd)" pytest -x -v -k test_zhihu_math_inline

test/data/zhihu-math-inline/src/simple.md

@@ -0,0 +1,16 @@
+inline math: $ x $ 哈哈
+
+inline math: $$
+y
+$$
+
+inline math: $
+y
+$
+
+block math:
+
+$$
+z
+$$
+

test/data/zhihu-math-inline/want/simple.md

@@ -0,0 +1,14 @@
+inline math: <img src="https://www.zhihu.com/equation?tex=%20x%20" alt=" x " class="ee_img tr_noresize" eeimg="1"> 哈哈
+
+inline math: <img src="https://www.zhihu.com/equation?tex=y" alt="y" class="ee_img tr_noresize" eeimg="1">
+
+inline math: <img src="https://www.zhihu.com/equation?tex=y" alt="y" class="ee_img tr_noresize" eeimg="1">
+
+block math:
+
+<img src="https://www.zhihu.com/equation?tex=z%5C%5C" alt="z\\" class="ee_img tr_noresize" eeimg="1">
+
+
+
+Reference:
+

test/test_md2zhihu.py

@@ -333,6 +333,9 @@ def test_zhihu_extrefs(self):
     def test_zhihu_rewrite(self):
         self._test_platform_no_push('zhihu-rewrite', 'simple.md', ['--rewrite', '^s', '/foo/'])
 
+    def test_zhihu_math_inline(self):
+        self._test_platform_no_push('zhihu-math-inline', 'simple.md', [])
+
     def test_zhihu_jekyll(self):
         self._test_platform_no_push('zhihu-jekyll', '2021-06-11-simple.md', ['--jekyll'])