修复OpenAI客户端初始化问题，支持纯文本输入（图片可选）

app.py

@@ -28,35 +28,26 @@ def image_to_base64(image):
     return None
 
 def call_step_api(image, prompt, model, temperature=0.7, max_tokens=2000):
-    """调用Step API进行图像分析和文本生成，支持CoT推理展示"""
-    
-    if image is None:
-        yield "❌ 请先上传一张图片", ""
-        return
+    """调用Step API进行分析，支持纯文本和图像+文本"""
     
     if not prompt:
-        yield "❌ 请输入提示词", ""
+        yield "", "❌ 请输入提示词"
         return
     
     if not STEP_API_KEY:
-        yield "❌ API密钥未配置。请在 Hugging Face Space 的 Settings 中添加 STEP_API_KEY 环境变量。", ""
+        yield "", "❌ API密钥未配置。请在 Hugging Face Space 的 Settings 中添加 STEP_API_KEY 环境变量。"
         return
     
-    # 转换图像为base64
-    try:
-        base64_image = image_to_base64(image)
-        if base64_image is None:
-            yield "❌ 图片处理失败", ""
-            return
-    except Exception as e:
-        yield f"❌ 图片处理错误: {str(e)}", ""
-        return
-    
-    # 构造消息
-    messages = [
-        {
-            "role": "user",
-            "content": [
+    # 构造消息内容
+    if image is not None:
+        # 有图片的情况
+        try:
+            base64_image = image_to_base64(image)
+            if base64_image is None:
+                yield "", "❌ 图片处理失败"
+                return
+                
+            message_content = [
                 {
                     "type": "image_url",
                     "image_url": {
@@ -69,14 +60,39 @@ def call_step_api(image, prompt, model, temperature=0.7, max_tokens=2000):
                     "text": prompt
                 }
             ]
+        except Exception as e:
+            yield "", f"❌ 图片处理错误: {str(e)}"
+            return
+    else:
+        # 纯文本的情况
+        message_content = prompt
+    
+    # 构造消息
+    messages = [
+        {
+            "role": "user",
+            "content": message_content
         }
     ]
     
-    # 创建OpenAI客户端
+    # 创建OpenAI客户端 - 修复初始化问题
     try:
-        client = OpenAI(api_key=STEP_API_KEY, base_url=BASE_URL)
+        # 设置环境变量方式，避免直接传递参数
+        os.environ['OPENAI_API_KEY'] = STEP_API_KEY
+        os.environ['OPENAI_BASE_URL'] = BASE_URL
+        client = OpenAI(
+            api_key=STEP_API_KEY,
+            base_url=BASE_URL
+        )
+    except TypeError:
+        # 如果上面的方式失败，尝试只用必要参数
+        try:
+            client = OpenAI()
+        except Exception as e:
+            yield "", f"❌ 客户端初始化失败: {str(e)}"
+            return
     except Exception as e:
-        yield f"❌ 客户端初始化失败: {str(e)}", ""
+        yield "", f"❌ 客户端初始化失败: {str(e)}"
         return
     
     try:
@@ -162,16 +178,16 @@ with gr.Blocks(title="Step-3", theme=gr.themes.Soft()) as demo:
         with gr.Column(scale=1):
             # 输入区域
             image_input = gr.Image(
-                label="上传图片",
+                label="上传图片（可选）",
                 type="pil",
                 height=300
             )
             
             prompt_input = gr.Textbox(
                 label="提示词",
-                placeholder="例如：这是什么？请详细描述",
+                placeholder="输入你的问题或描述...",
                 lines=3,
-                value="请详细描述这张图片的内容。"
+                value=""
             )
             
             with gr.Accordion("高级设置", open=False):