python - 错误 :not all arguments converted during string formatting

Question

我有这个注册页面，当我提交表单时出现此错误:并非所有参数都在字符串格式化期间转换

class RegistrationForm(Form):
email = StringField('Email address')
password = PasswordField('password')
name = StringField('Name')

@app.route('/register/', methods=['GET', 'POST'])
def register():
try:
    form = RegistrationForm(request.form)
    if request.method == 'POST':
        email = form.email.data
        password = sha256_crypt.encrypt((str(form.password.data)))
        con = connection()
        cur=con.cursor()
        x = cur.execute("SELECT * FROM user WHERE username = (%s)",(thwart(email)))
        if int(x) > 0:
            return render_template('register.html',form=form)
        else:
            cur.execute("INSERT INTO user (username,password,name) VALUES (%s,%s,%s);",(thwart(email),thwart(password),thwart(name),))
            con.commit()
            cur.close()
            con.close()
            return redirect(url_for('dashboard'))

    return render_template('register.html', form=form)
except Exception as e:
    return str(e)

Answer 1

x = cur.execute("SELECT * FROM user WHERE username = (%s)",(thwart(email)))

execute 的第二个参数应该是一个元组，你缺少一个 ,:

cur.execute("SELECT * FROM user WHERE username = (%s)",(thwart(email),))

我猜你也不需要 %s 周围的 () 但这取决于你的表的实际外观。

进一步说明:

('str') 将求值为字符串 'str'，而不是包含它的元组。

为了创建一个元组，您必须包含一个逗号:('str',)。