add {% vm %} to make the table cell virtically merged within a {% for %}

docxtpl/__init__.py

@@ -84,7 +84,17 @@ class DocxTemplate(object):
             # This is mandatory to have jinja2 generating correct xml code
             pat = r'<w:%(y)s[ >](?:(?!<w:%(y)s[ >]).)*({%%|{{)%(y)s ([^}%%]*(?:%%}|}})).*?</w:%(y)s>' % {'y':y}
             src_xml = re.sub(pat, r'\1 \2',src_xml,flags=re.DOTALL)
-
+        
+        # add vMerge
+        # use {% vm %} to make this table cell and its copies be vertically merged within a {% for %}
+        pat_vm = r'(<\/w:tcPr>.*)(<\/w:tcPr>)(.*?){%vm%}.*?<w:t>(.*?)(<\/w:t>)'
+        def vMerge(m):
+            return m.group(1) + '<w:vMerge {% if loop.first %}w:val="restart"{% endif %}/>' + m.group(2) + m.group(3) + "{% if loop.first %}"+ m.group(4) +"{% endif %}" + m.group(5)
+        pat_num_vm = re.compile(r'{%vm%}')
+        num = len(pat_num_vm.findall(src_xml))
+        for i in range(0,num):
+            src_xml = re.sub(pat_vm,vMerge,src_xml)
+        
         def clean_tags(m):
             return m.group(0).replace(r"&#8216;","'").replace('&lt;','<').replace('&gt;','>')
         src_xml = re.sub(r'(?<=\{[\{%])(.*?)(?=[\}%]})',clean_tags,src_xml)