title: python requests image upload fails to drf
body: <pre><code>    import json
      import requests
  
      user_f = open('categories.json',)
      users = json.load(user_f)
  
  
      media_api = 'http://127.0.0.1:8000/api/categories/'
  
      files=[
          ('category_image', (&quot;Traditional-Art.png&quot;, open(&quot;Traditional-Art.png&quot;,'rb'),'image/jpeg'))
      ]
  
      json = {
          &quot;category_name&quot;: &quot;cat&quot;,
          &quot;category_description&quot;: &quot;desc&quot;,
          &quot;user&quot;: 16
      }
  
      headers = {
                  &quot;Accept&quot;: 'application/json, text/plain, */*',
                  &quot;enctype&quot;:&quot;multipart/form-data&quot;
              }
  
      response = requests.request(&quot;POST&quot;, media_api, headers=headers, data=json, files=files)
      print(response.json())
  </code></pre>
  <p>Here, i am trying to upload image to django rest-framework and getting below error</p>
  <pre><code>`{u'category_image': [u'Upload a valid image. The file you uploaded was either not an image or a corrupted image.']}`
  </code></pre>
  <p>this works when image is jpg format but, not working in png .
  Am i missing anything or do i need to modify something ?</p>
  <p>Please take a look</p>