https://cloud.google.com/python/django/flexible-environment

host = '127.0.0.1' also changed to 35.196.etc
user = 'me'
password = 'pwd'

conn1 = pymysql.connect(host=host,
                         user=user,
                         password=password,
                         db='retail_data')
cur1 = conn1.cursor()

"listening on 127.0.0.1:3306 for scoviileapp:us-east1:retail18
ready for new connections"

gcloud app deploy

https://scovilleapp.appspot.com/search/?fname=james&mname=g&lname=stahl&street_num=1045&street_name=beck&street_type=rd&state=OH&zip=48233

app.yaml
# [START django_app]
# [START runtime]
runtime: python
threadsafe: yes
env: flex
entrypoint: gunicorn -b :$PORT scoville_matching_app.wsgi

beta_settings:
   cloud_sql_instances: 'scovilleapp:us-east1:retail18'

runtime_config:
  python_version: 3.5
# [END runtime]

handlers:
    - url: /static
static_dir: static/
    - url: /.*
script: main.application

# Only pure Python libraries can be vendored
# Python libraries that use C extensions can
# only be included if they are part of the App Engine SDK

#[START env]
env_variables:
    # Replace user, password, database, and instance connection name with the values obtained
    # when configuring your Cloud SQL instance.
    SQLALCHEMY_DATABASE_URI: >-
      mysql+pymysql://root:secret@/retail_service_data?unix_socket=/cloudsql/scovilleapp:us-east1:retail18

My settings file:

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


ALLOWED_HOSTS = ['*']


# Application definition

INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'scovilleapp', #name of the app we added
]


ROOT_URLCONF = 'scoville_matching_app.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'scoville_matching_app.wsgi.application'


# Database
# https://docs.djangoproject.com/en/2.0/ref/settings/#databases

# Check to see if MySQLdb is available; if not, have pymysql masquerade as
# MySQLdb. This is a convenience feature for developers who cannot   install
# MySQLdb locally; when running in production on Google App Engine Standard
# Environment, MySQLdb will be used.
try:
    import MySQLdb  # noqa: F401
except ImportError:
    import pymysql
    pymysql.install_as_MySQLdb()


# [START dbconfig]
DATABASES = {
    'default': {
       # If you are using Cloud SQL for MySQL rather than PostgreSQL, set
    # 'ENGINE': 'django.db.backends.mysql' instead of the following.
    'ENGINE': 'django.db.backends.mysql',
    'NAME': 'retail_service_data',
    'USER': 'me',
    'PASSWORD': 'pwd',
    # For MySQL, set 'PORT': '3306' instead of the following. Any Cloud
    # SQL Proxy instances running locally must also be set to tcp:3306.
    'PORT': '3306',
    }
}
# [END db_setup]
# In the flexible environment, you connect to CloudSQL using a unix socket.
# Locally, you can use the CloudSQL proxy to proxy a localhost connection
# to the instance
DATABASES['default']['HOST'] = '/cloudsql/scovilleapp:us-east1:retail18'
if os.getenv('GAE_INSTANCE'):
    pass
else:
    DATABASES['default']['HOST'] = '127.0.0.1'
# [END dbconfig]

# Password validation
# https://docs.djangoproject.com/en/2.0/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME':   'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# [START staticurl]
# Fill in your cloud bucket and switch which one of the following 2 lines
# is commented to serve static content from GCS
# STATIC_URL = 'https://storage.googleapis.com/<your-gcs-bucket>/static/'
STATIC_URL = 'https://storage.googleapis.com/scovilleapp/static/'
STATIC_ROOT = os.path.join(BASE_DIR, 'static')