程序应从文件中读取并返回字典，但返回类型错误

def read_dict_from_file(file_path):
    try:
        with open(file_path, 'r') as file:
            content = file.read()
            # 根据文件类型进行解析
            if file_path.endswith('.json'):
                import json
                data = json.loads(content)
            else:
                # 假设文件内容为每行一个键值对，以等号分隔
                data = {}
                lines = content.split('\n')
                for line in lines:
                    key, value = line.split('=')
                    data[key.strip()] = value.strip()
            # 确保返回类型为字典
            if isinstance(data, dict):
                return data
            else:
                return None
    except Exception as e:
        print("Error: ", e)
        return None

# 调用示例
file_path = 'data.txt'
result = read_dict_from_file(file_path)
if result is not None:
    print("读取成功：", result)
else:
    print("读取失败")