Postman的Binary方式传送数据，requests实现

问题来源及背景

最近在学习ES，在批量上传数据的时候卡住了，requests上传文件的时候一般用的是

url = 'http://127.0.0.1:9200/_bulk'
files = {
      "field" : open(filename, mode='rb')
    }
requests.post(url, data=files, headers={'Content-Type':'binary'})

但是上传的过程中ES一直报错，信息如下

{"error":{"root_cause":[{"type":"parse_exception","reason":"Failed to derive 
xcontent"}],"type":"parse_exception","reason":"Failed to derive xcontent"},"status":400}

但是利用postman的binary上传时却是正确的，如下图

解决

多方查找后并没有结果，后来去requests的官方文档上找到了一种解决方式：

with open(filename, 'rb') as f:
    r = requests.post(url, data=f)

原文：

Streaming Uploads

Requests supports streaming uploads, which allow you to send large streams or files without reading them into memory. To stream and upload, simply provide a file-like object for your body:

with open('massive-body', 'rb') as f:
    requests.post('http://some.url/streamed', data=f)