I use handlebars to render html

but the error is reported when it runs. Does anyone know why

Error: 500 Internal Server Error
Sorry, the requested URL "http://127.0.0.1:5432/" caused an error:

Internal Server Error
Exception:
SyntaxError("invalid syntax", ("/Users/Jyue/Desktop/code/exercises/2018-05-31/views/index.html", 21, 30, ""                    ", _str(/each), "\\n"\\\n"))
Traceback:
Traceback (most recent call last):
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 862, in _handle
    return route.call(**args)
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 1740, in wrapper
    rv = callback(*a, **ka)
  File "/Users/Jyue/Desktop/code/exercises/2018-05-31/main.py", line 48, in index
    return template("index")
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 3619, in template
    return TEMPLATES[tplid].render(kwargs)
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 3409, in render
    self.execute(stdout, env)
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 3396, in execute
    eval(self.co, env)
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 189, in __get__
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/Users/Jyue/venv1/lib/python3.6/site-packages/bottle.py", line 3354, in co
    return compile(self.code, self.filename or "<string>", "exec")
  File "/Users/Jyue/Desktop/code/exercises/2018-05-31/views/index.html", line 21
    "                    ", _str(/each), "\n"\
                                 ^
SyntaxError: invalid syntax