python - Flask User Page with ID -

i want have user page (/users/). when open /users/, should see own user profile (if logged in, else: error) when giev command, /users/?uid=2999 should laod user info of user uid=2999. works, if signed in see own profile works too. if not signed in, there following error:

bad request  browser (or proxy) sent request server not understand. 

that's code snippet:

@app.route('/users/') def users():     if 'logged_in' in session:         ret = 0         user = session['uid']         c, conn = dbconnect.conn()         data = c.execute("select * users uid = (%s)", (user))         if int(data) == 0:             flash("error! please send report @ martin@tekkkz.com!")         else:             data = c.fetchone()             ret = 1         c.close()         conn.close()         gc.collect()         if ret:             return render_template("users.html", nav=2, user=data)     elif request.args['uid']:         ret = 0         user = request.args['uid']         c, conn = dbconnect.conn()         data = c.execute("select * users uid = (%s)", (user))         if int(data) == 0:             flash("invalid user-id. user doesn't exist!")         else:             data = c.fetchone()             ret = 1         c.close()         conn.close()         gc.collect()         if ret:             return render_template("users.html", nav=2, user=data)     else:         flash("you need logged in see own profile!")     return redirect(url_for('login')) 

why there bad reqquest error ?

the problem line, when not logged in, , 'uid' not in query string.

elif request.args['uid']: 

flask raises http error when fails find key in args.

instead should have

elif 'uid' in request.args: