WTForms 在 Heroku 上引发“TypeError：'unicode' 没有缓冲区接口”答案

【问题标题】：WTForms raises "TypeError: 'unicode' does not have the buffer interface" on HerokuWTForms 在 Heroku 上引发“TypeError：'unicode' 没有缓冲区接口”
【发布时间】：2016-03-05 15:47:20
【问题描述】：

当我在 Heroku 上运行我的应用程序并提交 Flask-WTF 表单时，我得到以下回溯，错误为 TypeError: 'unicode' does not have the buffer interface。在本地运行应用程序有效。从回溯来看，Flask-WTF 验证 CSRF 令牌似乎存在问题。为什么会出现此错误，如何解决？

Exception on /restaurants/1/menu/add/ [POST]
Traceback (most recent call last):
  File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/app/.heroku/python/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/app/restaurantApp/views.py", line 95, in newMenuItem
    if form.validate_on_submit():
  File "/app/.heroku/python/lib/python2.7/site-packages/flask_wtf/form.py", line 166, in validate_on_submit
    return self.is_submitted() and self.validate()
  File "/app/.heroku/python/lib/python2.7/site-packages/wtforms/form.py", line 310, in validate
    return super(Form, self).validate(extra)
  File "/app/.heroku/python/lib/python2.7/site-packages/wtforms/form.py", line 152, in validate
    if not field.validate(self, extra):
  File "/app/.heroku/python/lib/python2.7/site-packages/wtforms/fields/core.py", line 204, in validate
    stop_validation = self._run_validation_chain(form, chain)
  File "/app/.heroku/python/lib/python2.7/site-packages/wtforms/fields/core.py", line 224, in _run_validation_chain
    validator(form, self)
  File "/app/.heroku/python/lib/python2.7/site-packages/flask_wtf/form.py", line 109, in validate_csrf_token
    if not validate_csrf(field.data, self.SECRET_KEY, self.TIME_LIMIT):
  File "/app/.heroku/python/lib/python2.7/site-packages/flask_wtf/csrf.py", line 111, in validate_csrf
    return safe_str_cmp(hmac_compare, hmac_csrf)
  File "/app/.heroku/python/lib/python2.7/site-packages/werkzeug/security.py", line 117, in safe_str_cmp
    return _builtin_safe_str_cmp(a, b)
TypeError: 'unicode' does not have the buffer interface

<form method="POST">
    {{ form.hidden_tag() }}
    <input type="submit" value="Add">
</form>

@app.route("/restaurants/<int:restaurant_id>/menu/add/", methods=["GET", "POST"])
def newMenuItem(restaurant_id):
    form = menuItemForm()

    if form.validate_on_submit():
        flash("new item added")
        return redirect(url_for("restaurantMenu"))
    else:
        return render_template("newMenuItem.html", form=form)

【问题讨论】：

你在本地使用 Python 2.7 吗？

标签： python heroku flask wtforms flask-wtforms

【解决方案1】：

您有一个非常旧的 Werkzeug 版本。请参阅this bug report，并在 2014 年发布了修复程序。Werkzeug 正在比较 Flask-WTF 用于 CSRF 的方法中的错误数据。升级您的 Werkzueg 版本并将其记录在您的需求文件中。今天的当前版本是 0.11.4。

pip install -U Werkzeug

Werkzeug==0.11.4

鉴于您使用的是非常过时的 Werkzeug 版本，您应该确保您的其他库也是最新的。

【讨论】：