刷新Spotify Access Token时遭遇Error 400错误求助

我尝试使用refresh token刷新Spotify Access Token，已遵循Spotify官方文档操作，且尝试寻找解决方案但未能解决问题。

用于刷新操作的代码 #

def refresh_the_token():
    auth_client = client_id + ":" + client_secret
    auth_encode = 'Basic ' + base64.b64encode(auth_client.encode()).decode()

    headers = {
        'Authorization': auth_encode,
        'Content - Type': 'application/x-www-form-urlencoded'
    }

    data = {
        'grant_type': 'refresh_token',
        'refresh_token': refresh_token
    }

    response = requests.post('https://accounts.spotify.com/api/token', data=data, headers=headers)  # sends request off to spotify

    if response.status_code == 200:  # checks if request was valid
        print("The request to went through we got a status 200; Spotify token refreshed")
        response_json = response.json()
        new_expire = response_json['expires_in']
        print("the time left on new token is: " + str(new_expire / 60) + "min")  # says how long
        return response_json["access_token"]
    else:
        print("ERROR! The response we got was: " + str(response))

遇到的错误 #

<html>

<head>

<meta http-equiv="content-type" content="text/html;charset=utf-8">
<title>400 Bad Request</title>

</head>

<body text=#000000 bgcolor=#ffffff>

<h1>Error: Bad Request</h1>
<h2>Your client has issued a malformed or illegal request.</h2>
<h2></h2>

</body>

</html>

Spotify官方文档（请求刷新访问令牌）核心要求 #

• 使用POST请求访问https://accounts.spotify.com/api/token
• 请求头必须包含：
  • Authorization: Basic <base64编码的client_id:client_secret>
  • Content-Type: application/x-www-form-urlencoded
• 请求体必须携带两个参数：
  • grant_type=refresh_token
  • refresh_token=<你的有效刷新令牌>

问题排查与修复方案 #

1. 修复请求头的Content-Type字段
   代码中'Content - Type'存在多余空格，这会导致Spotify无法正确识别请求格式，是引发400错误的直接原因。正确的字段名应为'Content-Type'。

2. 确保base64编码无异常
   拼接client_id和client_secret时避免多余空格，编码后记得去除可能的换行或空白字符。

3. 验证refresh_token有效性
   确认refresh_token是首次授权流程中正确获取的，未被撤销或过期。

修复后的代码示例 #

def refresh_the_token():
    auth_client = f"{client_id}:{client_secret}"
    # 规范编码流程，避免异常字符
    auth_encode = 'Basic ' + base64.b64encode(auth_client.encode('utf-8')).decode('utf-8').strip()

    headers = {
        'Authorization': auth_encode,
        'Content-Type': 'application/x-www-form-urlencoded'  # 移除空格，修正字段名
    }

    data = {
        'grant_type': 'refresh_token',
        'refresh_token': refresh_token
    }

    response = requests.post('https://accounts.spotify.com/api/token', data=data, headers=headers)

    if response.status_code == 200:
        print("请求成功，状态码200；Spotify令牌已刷新")
        response_json = response.json()
        new_expire = response_json['expires_in']
        print(f"新令牌剩余有效期：{new_expire / 60:.2f}分钟")
        return response_json["access_token"]
    else:
        # 输出更详细的错误信息，便于进一步排查
        print(f"错误！响应状态码：{response.status_code}")
        print(f"错误响应内容：{response.text}")

内容的提问来源于stack exchange，提问作者BGMine 13