I POST my image by python through WP REST API, but the response is just the array of items in media library - wordpress-rest-api

Question

First of all, I have found out what's wrong with my python code, but I really want some one to tell me how it popped out because I'm just a noob amateur.
I tried to post my album collected on my wordpress by using my python script as usual, but I got an unexpected throw-out when it start to image upload. My img upload function just like this:
def restImgUL(imgPath,imgName,token):
url='http://www.rainloongmusic.com/wp-json/wp/v2/media/'
file_extension = os.path.splitext(imgPath)[-1]
img = open(imgPath,'rb')
imgName = imgName.replace(";","")
_json = {
"title":imgName,
'caption': imgName,
"alt_text":imgName,
"description":imgName,
"status":"publish"
}
image_name = f"{imgName}{file_extension}"
headers = { 'Content-Type': '','Content-Disposition' : 'attachment; filename=%s'%image_name.encode("utf-8").decode("latin1"),"Authorization":"Bearer %s"%token}
res = requests.post(url=url,data=img,headers=headers,json=_json)
rrr = res.json()
if "id" in rrr:
return rrr["id"]
else:
print(rrr)
sys.exit()
The wrong response is an array include items in my first page of media library. I found some clues in rest api handbooks. If I attempt to GET /wp/v2/media, response will be like what I've recieved. But I use POST type request in my python code, I don't really understand what happened there. I have no choice but to try some other methods to bypass this problem. I tried to make a new endpoint and write something like this:
add_action( 'rest_api_init', function () {
register_rest_route( 'rlra/v1', '/media', array(
'methods' => 'POST',
'callback' => 'cmupload',
) );
} );
function cmupload(){
return "This is a test!!!"
}
However, I got rest_no_route when I POST to it. I changed the methods to GET eventually, and got the right text from my server. I think maybe something changed my POST request into a GET one? I tried to figure out with Charles, and found my connection with 302 permanent redirect. So I check my request link and change http into https, everything works.
So, could anyone tell me why a 302 redirect will change my POST request into GET, I've been worn-out due to the lost letter "s" in these days.