GAEでPythonをデプロイする

# coding: utf-8
import os
import io
import time
import string
import random
import datetime
from flask import Flask, render_template, request, redirect, url_for, send_from_directory,send_file
from flask_cors import CORS
import inspect
import pandas as pd


app = Flask(__name__)
CORS(app)

@app.route('/',methods=["GET","POST"])
def hello():
    df = pd.DataFrame({'A':[i for i in range(100)]})
    a = str(list(df.T.to_dict().values()))
    print(a)
    return a
if __name__ == "__main__":
    pass
    #app.run(host='127.0.0.1',debug=True)

Flask==1.1.2
Flask-Cors==3.0.10
numpy==1.18.0
pandas==1.2.0

runtime: python37 # or another supported version
service: default
instance_class: B1
basic_scaling:
  max_instances: 1
  idle_timeout: 5m