flask 读取请求body报错

from flask import Flask,request


app=Flask(__name__)


@app.route("/abc",methods=["post"])
def index():
    print(request.body)
    return "cd",200

if __name__=="__main__":
    app.run()

报错

Traceback (most recent call last):
  File "/Users/jiangyd/PycharmProjects/untitled16/venv/lib/python3.7/site-packages/flask/app.py", line 2070, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/jiangyd/PycharmProjects/untitled16/venv/lib/python3.7/site-packages/flask/app.py", line 1515, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/jiangyd/PycharmProjects/untitled16/venv/lib/python3.7/site-packages/flask/app.py", line 1513, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/jiangyd/PycharmProjects/untitled16/venv/lib/python3.7/site-packages/flask/app.py", line 1499, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
  File "b.py", line 9, in index
    print(request.body)
AttributeError: 'Request' object has no attribute 'body'