title: ModuleNotFoundError: No module named 'flask_session'
body: <p>I have a simple python file that I am trying to set up to utilize sessions, when i run the file I am receiving the error below: </p>
  
  <blockquote>
    <p>ModuleNotFoundError: No module named 'flask_session'</p>
  </blockquote>
  
  <p>I believe I am importing the module properly, is there anything else that I can check to set this up properly?</p>
  
  <pre><code>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)
  </code></pre>
  
  <p>Here is the traceback ( most recent call last )</p>
  
  <pre><code>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())
  </code></pre>