設定をsettings.pyから読み取るだけではなく環境変数からも取得できるようにします。

app.py

@@ -1,18 +1,18 @@
 import requests
 from requests_oauthlib import OAuth1
 from bitcoinrpc.authproxy import AuthServiceProxy, JSONRPCException
-import settings
 import json
 import threading
 import time
 # import traceback
+from bot_config import BotConfig
 
 
 class XP_RPC():
 
     def __init__(self):
         self.connection = AuthServiceProxy(
-            settings.RPC_URL % (settings.rpc_user, settings.rpc_password))
+            BotConfig.RPC_URL % (BotConfig.RPC_USER, BotConfig.RPC_PASSWORD))
         self.tax = 1.0
 
     def get_address(self, name):
@@ -65,10 +65,10 @@ class Twitter():
 
     def __init__(self):
         self.xpd = XP_RPC()
-        self.auth_stream = OAuth1(settings.CONSUMER_KEY_STREAM, settings.CONSUMER_SECRET_STREAM,
-                                  settings.ACCESS_TOKEN_STREAM, settings.ACCESS_TOKEN_SECRET_STREAM)
-        self.auth_reply = OAuth1(settings.CONSUMER_KEY_REPLY, settings.CONSUMER_SECRET_REPLY,
-                                 settings.ACCESS_TOKEN_REPLY, settings.ACCESS_TOKEN_SECRET_REPLY)
+        self.auth_stream = OAuth1(BotConfig.CONSUMER_KEY_STREAM, BotConfig.CONSUMER_SECRET_STREAM,
+                                  BotConfig.ACCESS_TOKEN_STREAM, BotConfig.ACCESS_TOKEN_SECRET_STREAM)
+        self.auth_reply = OAuth1(BotConfig.CONSUMER_KEY_REPLY, BotConfig.CONSUMER_SECRET_REPLY,
+                                 BotConfig.ACCESS_TOKEN_REPLY, BotConfig.ACCESS_TOKEN_SECRET_REPLY)
         self.tweets = []
 
     def reply(self, text, reply_token):

bot_config.py

@@ -0,0 +1,55 @@
+"""
+Configuration object that does not need to instantiate.
+
+Usage:
+> from bot_config import BotConfig
+> BotConfig.SOME_PROPERTY
+"""
+import os
+from collections import ChainMap
+
+DEFAULTS = {
+    'CONSUMER_KEY': None,
+    'CONSUMER_SECRET': None,
+    'ACCESS_TOKEN': None,
+    'ACCESS_TOKEN_SECRET': None,
+    'RPC_URL': None,
+    'RPC_USER': None,
+    'RPC_PASSWORD': None,
+}
+
+
+class Singleton(type):
+    """Make class to be a singleton"""
+    _instances = {}
+
+    def __call__(self, *args, **kwargs):
+        """If instance exists, just return it."""
+        if self not in self._instances:
+            self._instances[self] = super().__call__(*args, **kwargs)
+        return self._instances[self]
+
+
+class BotConfigFactory(object, metaclass=Singleton):
+    """Factory provides BotConfig instance as a singleton."""
+
+    def __init__(self):
+        """Pick variables from environment variables, `setting.py`, DEFAULTS.
+
+        Only the keys in `settings.py` are case insensitive."""
+        environments = dict((key, val) for key, val in os.environ.items() if key in DEFAULTS)
+        from_settings = {}
+        try:
+            import settings
+            from_settings = dict((key.upper(), getattr(settings, key)) for key in dir(settings)
+                                 if key.upper() in DEFAULTS)
+        except ModuleNotFoundError:
+            print('settings.py not found. continue with using environment variables.')
+
+        _configs = ChainMap(environments, from_settings, DEFAULTS)
+
+        for key, val in _configs.items():
+            setattr(self, key, val)
+
+
+BotConfig = BotConfigFactory()