gistfile1.js

$("#upload_btn").click(function(){

  		var fileIn = $("#fileToUpload")[0];
			 if (fileIn.files === undefined || fileIn.files.length == 0) {
       			alert("Please select a file");
        		return;
   			 }

   			 var file = fileIn.files[0];
   			 var fotka = new FormData()
   			 fotka.append('file' , file)
   			 alert(file.type);
    		//Show the progress bar
    		$("#progressbar").show();
    		
   			$.ajax({
        		url: "/proba",
        		type: "POST",
       			data: fotka,
        		processData: false, 
        		contentType: file.type, 
        		success: function(){
            	$("#progressbar").hide();},
       			error: function(){alert("Failed");},
       			xhr: function() {
            		myXhr = $.ajaxSettings.xhr();
            		if(myXhr.upload){
                	myXhr.upload.addEventListener('progress',showProgress, false);
           			} else {
                		console.log("Upload progress is not supported.");
            		}
            	return myXhr;
        		}
    		});


		});
    
    

gistfile2.py

@app.route('/proba' , methods= ['POST'])
def proba():

  print request.environ
  print request.environ['wsgi.input']
  """{'wsgi.multiprocess': False, 'HTTP_COOKIE': 'session="1FXRQXWcbS5MIp4rSxwZNzV37P
o=?_id=Uyd7aFx4YzVceGYyXHgxZVx4YmN5XHhhYVBsXHgwM1x4OWZjXHg5NFRceDkyJwpwMQou&csrf
=UyczNmMzZDU4Mzk3ZDA1YTFmN2U3NzljMDNmZDRmOWIzYzNmNTNiMjk1JwpwMQou"', 'SERVER_SOF
TWARE': 'Werkzeug/0.8.3', 'SCRIPT_NAME': '', 'REQUEST_METHOD': 'POST', 'PATH_INF
O': '/proba', 'HTTP_ORIGIN': 'http://localhost:5000', 'SERVER_PROTOCOL': 'HTTP/1
.1', 'QUERY_STRING': '', 'werkzeug.server.shutdown': <function shutdown_server a
t 0x038A1870>, 'CONTENT_LENGTH': '387135', 'HTTP_ACCEPT_CHARSET': 'windows-1251,
utf-8;q=0.7,*;q=0.3', 'HTTP_USER_AGENT': 'Mozilla/5.0 (Windows NT 6.1; WOW64) Ap
pleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31', 'HTTP_C
ONNECTION': 'keep-alive', 'HTTP_REFERER': 'http://localhost:5000/admin', 'SERVER
_NAME': '127.0.0.1', 'REMOTE_PORT': 53994, 'wsgi.url_scheme': 'http', 'SERVER_PO
RT': '5000', 'HTTP_X_REQUESTED_WITH': 'XMLHttpRequest', 'werkzeug.request': <Req
uest 'http://localhost:5000/proba' [POST]>, 'wsgi.input': <socket._fileobject ob
ject at 0x038A17B0>, 'HTTP_HOST': 'localhost:5000', 'wsgi.multithread': False, '
HTTP_ACCEPT': '*/*', 'wsgi.version': (1, 0), 'wsgi.run_once': False, 'wsgi.error
s': <open file '<stderr>', mode 'w' at 0x021450D0>, 'REMOTE_ADDR': '127.0.0.1',
'HTTP_ACCEPT_LANGUAGE': 'sr-RS,sr;q=0.8,en-US;q=0.6,en;q=0.4', 'CONTENT_TYPE': '
image/jpeg', 'HTTP_ACCEPT_ENCODING': 'gzip,deflate,sdch'}
<socket._fileobject object at 0x038A17B0>"""