ModuleNotFoundError：没有名为“flask_session”的模块

Question

新手上路，请多包涵

我有一个简单的 python 文件，我试图设置它来利用会话，当我运行该文件时，我收到以下错误：

ModuleNotFoundError：没有名为“flask_session”的模块

我相信我正在正确导入模块，还有什么我可以检查以正确设置它的吗？

 from flask import Flask, render_template, request, session
from flask_session import Session

app = Flask(__name__)

app.config["SESSION_PERMANENT"] = False
app.config["SESSION_TYPE"] = "filesystem"

Session(app)

@app.route("/", methods=["GET", "POST"])
def index():
    if session.get("notes") is None:
        session["notes"] = []

    if request.method == "POST":
        note = request.form.get("note")
        session["notes"].append(note)

    return render_template("index.html", notes=notes)

这是追溯（最近一次通话）

 File "c:\python37\lib\site-packages\flask\cli.py", line 325, in __call__
Open an interactive python shell in this frameself._flush_bg_loading_exception()

File "c:\python37\lib\site-packages\flask\cli.py", line 313, in _flush_bg_loading_exception
reraise(*exc_info)

File "c:\python37\lib\site-packages\flask_compat.py", line 35, in reraise
raise value

File "c:\python37\lib\site-packages\flask\cli.py", line 302, in _load_app
self._load_unlocked()

File "c:\python37\lib\site-packages\flask\cli.py", line 317, in _load_unlocked
self._app = rv = self.loader()

File "c:\python37\lib\site-packages\flask\cli.py", line 372, in load_app
app = locate_app(self, import_name, name)

File "c:\python37\lib\site-packages\flask\cli.py", line 242, in locate_app
'\n\n{tb}'.format(name=module_name, tb=traceback.format_exc())