Question

我试图将我写的一些javascript代码转换为Python，但我仍然卡在传递数据b / t PIL和Requests对象上。

我的python脚本将图像下载到内存中：

from PIL import Image
import urllib2
import cStringIO

def fetch_image_to_memory(url):
   req = urllib2.Request(url, headers={
                         'User-Agent': "Mozilla / 5.0 (X11; U; Linux i686) Gecko / 20071127 Firefox / 2.0.0.11"})
   con = urllib2.urlopen(req)
   imgData = con.read()
   return Image.open(cStringIO.StringIO(imgData))

我希望将其添加到form data进行POST操作。当文件在磁盘上时，此代码成功：

from requests_toolbelt import MultipartEncoder
import requests
url = 'https://us-west-2.api.scaphold.io/graphql/some-gql-endpoint'

multipart_data = MultipartEncoder(
    fields={
         'query':'some-graphql-specific-query-string',
        'variables': '{ "input": {"blobFieldName": "myBlobField" }}',

        ## `variables.input.blobFieldName` must hold name 
        ## of Form field w/ the file to be uploaded
        'type': 'application/json',
        'myBlobField': ('example.jpg', img, 'image/jpeg')
    }
)
req_headers = {'Content-Type':multipart_data.content_type, 
             'Authorization':'Bearer secret-bearer-token'}
r = requests.post(url, data=multipart_data, headers=req_headers)

但是，尝试从Image函数传入fetch_image_to_memory对象时：

 'myBlobField': ('example.jpg', image_object, 'image/jpeg')

...我收到错误：

Traceback (most recent call last):
  File "test-gql.py", line 38, in <module>
    'myBlobField': img
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 119, in __init__
    self._prepare_parts()
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 240, in _prepare_
parts
    self.parts = [Part.from_field(f, enc) for f in self._iter_fields()]
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 488, in from_fiel
d
    body = coerce_data(field.data, encoding)
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 466, in coerce_da
ta
    return CustomBytesIO(data, encoding)
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 529, in __init__
    buffer = encode_with(buffer, encoding)
  File "/home/bmp/code/wayhome/python-phash/requests_toolbelt/multipart/encoder.py", line 410, in encode_wi
th
    return string.encode(encoding)
AttributeError: 'JpegImageFile' object has no attribute 'encode'

我从open() docs知道它返回file类型的对象，但我在PIL中可以看到从Image转换为{{1}的唯一方法是通过使用file，将其写入磁盘。我可以写入磁盘，但我宁愿避开这一步，因为我正在处理大量图片。

是否可以将save()对象转换为Image类型？或者其他一些具有类似效果的解决方法？

Answer 1

MultipartEncoder可以使用字节字符串或文件对象，但PIL图像对象都不是。

您必须先创建内存中的文件对象：

from io import BytesIO

image_file = BytesIO()
img.save(image_file, "JPEG")
image_file.seek(0)

然后在帖子中使用 image_file ：

'myBlobField': ('example.jpg', image_file, 'image/jpeg')

如何使用带有请求的多部分POST发布Image对象？

1 个答案: