Python's tornado framework for image uploading and image resizing

Uploading of images

Upload the image using the form submission, the following is the HTML section, enctype= "Multipart/form-data" means not to encode the bytes, upload the file type to be specified. The type= "file" of the input tag specifies the type of upload.

<form action= "/" enctype= "Multipart/form-data" method= "POST" >  <input type= "file" name= "Headimg" > </form>

Here is the section that tornado accepts the file

Class Uploadhandler (Basehandler):  def post (self):    # This part is the uploaded file, want to see more can print self.request look at    # The file returns a list of elements for the dictionary    imgfile = self.request.files.get (' headimg ') for    the img in imgfile:      # img has three key-value pairs that can be passed by Img.keys ( View      # is ' filename ', ' body ', ' content_type ' clearly corresponds to filename, content (binary) and file type with      open ('./static/uploads/' + img[') FileName '], ' WB ') as F:        # File contents saved to '/static/uploads/{{filename} '        f.write (f[' body ')

This allows you to access the/static/uploads/file name

Modify the size of a picture

Below will write the resize to the picture

Class Uploadhandler (Basehandler): @tornado. web.authenticated def post (self): # It should be written to the above, in order to show that it was written in the function import time #    PIL is a module that operates on images in Python and is interesting to see the from PIL import image # can be used like a file, just stored in memory from Cstringio import Stringio # to determine the size of the upload file sizes size = Int (self.request.headers.get (' content-length ')) if size/1000.0 > 2000:self.write ("Upload picture not    can be greater than 2M. ") Imgfile = Self.request.files.get (' headimg ') for IMG in Imgfile: # renaming a file name = str (time.strftime ('%y%m%d% ')  ), Time.localtime ()) \ + ' _ ' + self.current_user + ' _headimg.png ' with open ('./static/uploads/' + name, ' WB ') As f: # Image has a variety of open methods, one is Image.open (' Xx.png ') # and the other is Image.open (Stringio (buffer)) Im = Image.open ( Stringio (img[' body ')) # Modify the picture size resize accept two parameters, the first one is the wide-height tuple data, the second is the processing of the picture details, this article represents anti-Aliasing im = Im.resize ((), image .        AntiAlias) # Open IO like a file Im_file = Stringio () im.save (im_file, format= ' png ') # This is what gets in IO Im_data= Im_file.getvalue () f.write (Im_data) 

This allows the file size to be modified when uploading