Google Cloud web app not displaying custom Python code-CodePudding

I currently have a "working" web app through Google Cloud's App Engine. The only thing that is being displayed when I visit my web app is "Welcome to my Python program!" that I have in my index.html file.

I'm trying to display the rest of the Python code that prints some strings regarding time. What I have in my files isn't working and I'm not sure what I am doing wrong. I've tried messing around with the Python code as I believe that is the issue. Maybe I'm not placing the call to the function in the right place?

Here is what I have as far as files go:

requirements.txt

Flask==2.0.2
pytz==2020.1
gunicorn==19.3.0

app.yaml

runtime: python
env: flex
entrypoint: gunicorn -b :$PORT main:app

runtime_config:
    python_version: 3

handlers:
- url: /static
  static_dir: static

- url: /.*
  script: auto

manual_scaling:
  instances: 1
resources:
  cpu: 1
  memory_gb: 0.5
  disk_size_gb: 10

main.py

import pytz
from datetime import datetime
from flask import Flask, render_template

app = Flask(__name__)

def all_about_time():
    #Prints local date.
    current_time = datetime.now()
    local_date = datetime.strftime(current_time, '%b %d, %Y')
    print('Today\'s date is: '    str(local_date))
        
    #Prints out the time on the east coast. Helps give context on market hours.    
    eastern_time = datetime.strftime(current_time.astimezone(pytz.timezone('US/Eastern')), '%I:%M %p')
    print('Time on the East Coast is currently: '   eastern_time)
    
    #This logic block dictates whether the market is closed or open. So far does not account for holidays.
    day_of_week = datetime.strftime(current_time.astimezone(pytz.timezone('US/Eastern')), '%A')
    dt_east = int(datetime.strftime(current_time.astimezone(pytz.timezone('US/Eastern')), '%H%M'))
    if 930 <= dt_east <= 1600 and (day_of_week != 'Saturday' and day_of_week != 'Sunday'):
        print('The market is open!')
    else:
        print('The market is closed.')

@app.route("/")
def hello():
    all_about_time()
    return render_template('index.html')

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <script src="{{ url_for('static', filename='script.js') }}"></script>
    <link type="text/css" rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>MyPythonProgram</title>
</head>
<body>
    <h1>Welcome to my Python Program!</h1>
</body>
</html>

CodePudding user response：

Try changing the last statement in all_about_time to:

    if 930 <= dt_east <= 1600 and (day_of_week != 'Saturday' and day_of_week != 'Sunday'):
        return('open')
    else:
        return('closed')

Then change the following:

@app.route("/")
def hello():
    status = all_about_time()
    return render_template('index.html', status=status)

Then change index.html:

<!DOCTYPE html>
<html lang="en">
<head>
    <script src="{{ url_for('static', filename='script.js') }}"></script>
    <link type="text/css" rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>MyPythonProgram</title>
</head>
<body>
    <h1>The market is {{ status }}</h1>
</body>
</html>

I encourage to read Flask's (excellent) documentation to understand how it works.

I've not run your code but, assuming that all_about_time time works, it prints a string to (standard) output. The hello run invokes all_about_time (which prints the string) and then (importantly) the function renders the index.html template which produces the output you observe Welcome to my Python Program!. Even though all_about_time printed something, the output went to the console and was not included in the page that was rendered in the browser.

With the minimal changes, I made:

all_about_time now returns a string (either open or closed).
hello invokes all_about_time and assigns the result (either openorclosed) to status`.
status is then passed to the template to be rendered
The template now includes a variable {{ status }} which will be replaced with the actual value of status i.e. (hopefully) open or closed