WTForms提高对Heroku的"TypeError: 'unicode' does not have the buffer interface"

Question

当我在 Heroku 上运行我的应用程序并提交 Flask-WTF 表单时，我收到以下回溯，错误TypeError: 'unicode' does not have the buffer interface。 在本地运行应用可以工作。 从回溯来看，Flask-WTF验证CSRF令牌似乎存在问题。 为什么我会收到此错误以及如何解决它？

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)

Answer 1

你有一个非常老版本的Werkzeug。 请参阅此错误报告，其中包含 2014 年发布的修复程序。 Werkzeug在Flask-WTF用于CSRF的方法中比较了错误的数据。 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。