400 错误请求：KeyError：“用户名”

Question

在测试此代码时，我收到错误“400 Bad Request: KeyError: 'username'”，我不知道为什么

这是代码，我正在使用烧瓶来做这个

@app.route('/')
def index():
if 'username' in session:
    username = session['username']
    return 'Logged in as ' + username + '<br>' + \
     "<b><a href = '/logout'>click here to log out</a></b>"
return  "You are not logged in <br><a href = '/login'></b>" + \
  "click here to log in</b></a>"

@app.route('/login', methods = ['GET', 'POST'])
def login():
if request.method == 'POST':
    session['username'] = request.form['username']
    return redirect(url_for('index'))
return '''

<form action = "" method = "post">
<p><input type = text name = username/></p>
<p><input type = submit value = Login /></p>
</form>

'''
@app.route('/logout')
def logout():
#remove the session from username if it is there
session.pop('username', None)
return redirect(url_for('index'))

Answer 1

您收到错误是因为没有键 username，很可能在 if request.method == 'POST' 块内的 request.form 对象中。这可能是因为您在 HTML 中创建表单的方式。您应该在字段属性周围加上引号，例如：

<form action="" method="post">
<p><input type="text" name="username" /></p>
<p><input type="submit" value="Login"/></p>
</form>