Jinja 2對於循環崩潰谷歌應用引擎

我有一個簡單的Jinja模板測試片段，我爲HTML模板編寫，但由於某些原因，循環崩潰在線應用引擎和devappserver。我嘗試用一個常量代替我的for循環的主題，以測試實際的循環，並根據Cloud SDK Shell錯誤消息將其隔離爲for循環的實際語法。代碼段出了什麼問題？Jinja 2對於循環崩潰谷歌應用引擎

錯誤：

File "C:\Users\Skyler\Documents\Reverie\reflect\templates\index.html", 
line 9, 
in template 
    {{% for test in my_list %}} 
TemplateSyntaxError: unexpected '%'

的index.html

<!DOCTYPE html> 
<html> 
<head> 
    <title>{{title}}</title> 
</head> 
<body> 
<h1> {{my_list[3]}} </h1> 
<ul> 
    {{% for test in my_list %}} 
    <li>{{my_list[1]}}</li> 
    {{% endfor %}} 
</ul> 
</body> 
</html>

test.py

import webapp2 
import jinja2 
import os 

template_dir = os.path.join(os.path.dirname(__file__), "templates") 
jinja_env = jinja2.Environment(loader = jinja2.FileSystemLoader(template_dir), autoescape = True) 

class Handler(webapp2.RequestHandler): 
    def write(self, *a, **kw): 
     self.response.write(*a, **kw) 

    def render_str(self, template, **params): 
     t = jinja_env.get_template(template) 
     return t.render(params) 

    def render(self, template, **kw): 
     self.write(self.render_str(template, **kw)) 

class MainPage(Handler): 
    """docstring for MainPage""" 
    def get(self): 
     self.render("index.html", title="Nani", my_list=[0,1,2,"string"]) 

app = webapp2.WSGIApplication([('/', MainPage),], debug=True)

的app.yaml

runtime: python27 
api_version: 1 
threadsafe: true 

handlers: 
- url:/
    script: test.app 

libraries: 
- name: jinja2 
    version: latest

Full Stacktrace

ERROR 2017-07-18 05:02:36,960 webapp2.py:1528] unexpected '%' 
Traceback (most recent call last): 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1511, in __call__ 
    rv = self.handle_exception(request, response, e) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1505, in __call__ 
    rv = self.router.dispatch(request, response) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1253, in default_dispatcher 
    return route.handler_adapter(request, response) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1077, in __call__ 
    return handler.dispatch() 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 547, in dispatch 
    return self.handle_exception(e, self.app.debug) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 545, in dispatch 
    return method(*args, **kwargs) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 22, in get 
    self.render("index.html", title="Nani", my_list=[0,1,2,"string"]) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 17, in render 
    self.write(self.render_str(template, **kw)) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 13, in render_s 
tr 
    t = jinja_env.get_template(template) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 719, in get_templa 
te 
    return self._load_template(name, self.make_globals(globals)) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 693, in _load_temp 
late 
    template = self.loader.load(self, name, globals) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\loaders.py", line 127, in load 
    code = environment.compile(source, name, filename) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 493, in compile 
    self.handle_exception(exc_info, source_hint=source) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\templates\index.html", line 9, 
in template 
    {{% for test in my_list %}} 
TemplateSyntaxError: unexpected '%' 
ERROR 2017-07-18 05:02:36,960 wsgi.py:279] 
Traceback (most recent call last): 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\google\appengine\runtime\wsgi.py", line 267, in Handle 
    result = handler(dict(self._environ), self._StartResponse) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1519, in __call__ 
    response = self._internal_error(e) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1511, in __call__ 
    rv = self.handle_exception(request, response, e) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1505, in __call__ 
    rv = self.router.dispatch(request, response) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1253, in default_dispatcher 
    return route.handler_adapter(request, response) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 1077, in __call__ 
    return handler.dispatch() 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 547, in dispatch 
    return self.handle_exception(e, self.app.debug) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\webapp2-2.3\webapp2.py", line 545, in dispatch 
    return method(*args, **kwargs) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 22, in get 
    self.render("index.html", title="Nani", my_list=[0,1,2,"string"]) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 17, in render 
    self.write(self.render_str(template, **kw)) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\test.py", line 13, in render_s 
tr 
    t = jinja_env.get_template(template) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 719, in get_templa 
te 
    return self._load_template(name, self.make_globals(globals)) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 693, in _load_temp 
late 
    template = self.loader.load(self, name, globals) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\loaders.py", line 127, in load 
    code = environment.compile(source, name, filename) 
    File "C:\Users\Skyler\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform 
\google_appengine\lib\jinja2-2.6\jinja2\environment.py", line 493, in compile 
    self.handle_exception(exc_info, source_hint=source) 
    File "C:\Users\Skyler\Documents\Reverie\reflect\templates\index.html", line 9, 
in template 
    {{% for test in my_list %}} 
TemplateSyntaxError: unexpected '%' 
INFO  2017-07-17 22:02:36,970 module.py:832] default: "GET/HTTP/1.1" 500 -

來源

2017-07-18 Skyler

這可能是因爲您似乎太多地使用了一個花括號。看看從docs循環：

<title>{% block title %}{% endblock %}</title> <ul> {% for user in users %} <li><a href="{{ user.url }}">{{ user.username }}</a></li> {% endfor %} </ul>

只有一個在聲明{% for user in users %}大括號，而你的語句使用兩個花括號：{{% for test in my_list %}}。

試試看：{% for test in my_list %}看看會發生什麼。

來源

2017-07-18 09:06:52

就是這樣，聖銳我花了這麼多時間盲目。有趣的是，額外的大括號可能會導致錯誤，任何想法爲什麼可能是這種情況，就解釋器生命週期而言？ – Skyler

@Skyler我認爲必須深入研究jinja2來源，找出原因。我同意它應該更優雅地失敗。 –

Jinja 2對於循環崩潰谷歌應用引擎

回答

相關問題