From d38746d2789bd4f9efe18bc03caf73c965bf4d8e Mon Sep 17 00:00:00 2001
From: Fabio Manganiello <blacklight86@gmail.com>
Date: Sun, 1 Dec 2019 23:35:05 +0100
Subject: [PATCH] Moved imports for extra dependencies inside the methods where
 they are actually used

---
 platypush/backend/assistant/google.py         | 21 ++++++++++---------
 platypush/backend/gps.py                      |  3 ++-
 .../backend/http/request/rss/__init__.py      | 10 +++++++--
 platypush/backend/inotify/__init__.py         |  2 +-
 platypush/backend/joystick.py                 |  3 ++-
 platypush/backend/kafka/__init__.py           |  3 +--
 platypush/backend/nfc.py                      |  8 ++++---
 platypush/backend/pushbullet/__init__.py      |  4 ++--
 platypush/backend/scard/__init__.py           | 10 ++++-----
 platypush/backend/wiimote.py                  |  4 +++-
 platypush/plugins/adafruit/io.py              |  3 +--
 platypush/plugins/assistant/echo/__init__.py  | 15 +++++++------
 .../plugins/assistant/google/pushtotalk.py    | 21 +++++++++++--------
 platypush/plugins/calendar/ical.py            |  3 +--
 .../plugins/camera/ir/mlx90640/__init__.py    | 18 +++++++++-------
 platypush/plugins/clipboard.py                |  4 ++--
 platypush/plugins/google/__init__.py          |  2 +-
 platypush/plugins/google/mail.py              |  2 --
 platypush/plugins/gpio/sensor/envirophat.py   |  4 ++--
 .../plugins/gpio/sensor/motion/pwm3901.py     |  7 ++++---
 platypush/plugins/http/request/rss.py         |  3 +--
 platypush/plugins/kafka.py                    |  4 ++--
 platypush/plugins/lastfm/__init__.py          |  3 ++-
 platypush/plugins/media/chromecast.py         |  6 +++---
 platypush/plugins/media/plex.py               |  6 +++---
 platypush/plugins/midi.py                     |  3 ++-
 platypush/plugins/mqtt.py                     |  3 ++-
 platypush/plugins/music/mpd/__init__.py       |  3 ++-
 .../plugins/switch/switchbot/__init__.py      |  4 ++--
 platypush/plugins/switch/tplink.py            |  4 ++--
 platypush/plugins/tts/google.py               |  6 +++---
 requirements.txt                              |  5 ++++-
 setup.py                                      |  4 ++--
 33 files changed, 112 insertions(+), 89 deletions(-)

diff --git a/platypush/backend/assistant/google.py b/platypush/backend/assistant/google.py
index 2a7bc853..858e1496 100644
--- a/platypush/backend/assistant/google.py
+++ b/platypush/backend/assistant/google.py
@@ -7,11 +7,6 @@ import json
 import os
 import time
 
-import google.oauth2.credentials
-
-from google.assistant.library import Assistant
-from google.assistant.library.event import EventType, AlertType
-
 from platypush.backend import Backend
 from platypush.message.event.assistant import \
     ConversationStartEvent, ConversationEndEvent, ConversationTimeoutEvent, \
@@ -83,17 +78,15 @@ class AssistantGoogleBackend(Backend):
         super().__init__(**kwargs)
         self.credentials_file = credentials_file
         self.device_model_id = device_model_id
+        self.credentials = None
         self.assistant = None
         self._has_error = False
 
-        with open(self.credentials_file, 'r') as f:
-            self.credentials = google.oauth2.credentials.Credentials(
-                token=None,
-                **json.load(f))
-
         self.logger.info('Initialized Google Assistant backend')
 
     def _process_event(self, event):
+        from google.assistant.library.event import EventType, AlertType
+
         self.logger.info('Received assistant event: {}'.format(event))
         self._has_error = False
 
@@ -149,8 +142,16 @@ class AssistantGoogleBackend(Backend):
             self.assistant.stop_conversation()
 
     def run(self):
+        import google.oauth2.credentials
+        from google.assistant.library import Assistant
+
         super().run()
 
+        with open(self.credentials_file, 'r') as f:
+            self.credentials = google.oauth2.credentials.Credentials(
+                token=None,
+                **json.load(f))
+
         while not self.should_stop():
             self._has_error = False
 
diff --git a/platypush/backend/gps.py b/platypush/backend/gps.py
index 418053cf..4729a0f6 100644
--- a/platypush/backend/gps.py
+++ b/platypush/backend/gps.py
@@ -1,4 +1,3 @@
-import gps
 import threading
 import time
 
@@ -49,6 +48,8 @@ class GpsBackend(Backend):
         self._devices = {}
 
     def _get_session(self):
+        import gps
+
         with self._session_lock:
             if not self._session:
                 self._session = gps.gps(host=self.gpsd_server, port=self.gpsd_port, reconnect=True)
diff --git a/platypush/backend/http/request/rss/__init__.py b/platypush/backend/http/request/rss/__init__.py
index d8a881a8..d8e0dc83 100644
--- a/platypush/backend/http/request/rss/__init__.py
+++ b/platypush/backend/http/request/rss/__init__.py
@@ -1,6 +1,5 @@
 import datetime
 import enum
-import feedparser
 import os
 
 from sqlalchemy import create_engine, Column, Integer, String, DateTime, \
@@ -20,7 +19,13 @@ Session = scoped_session(sessionmaker())
 
 
 class RssUpdates(HttpRequest):
-    """ Gets new items in an RSS feed """
+    """
+    Gets new items in an RSS feed
+
+    Requires:
+
+        * **feedparser** (``pip install feedparser``)
+    """
 
     user_agent = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) ' + \
                  'Chrome/62.0.3202.94 Safari/537.36'
@@ -80,6 +85,7 @@ class RssUpdates(HttpRequest):
         return response.get('content')
 
     def get_new_items(self, response):
+        import feedparser
         engine = create_engine('sqlite:///{}'.format(self.dbfile),
                                connect_args={'check_same_thread': False})
 
diff --git a/platypush/backend/inotify/__init__.py b/platypush/backend/inotify/__init__.py
index 8dae146b..c9085393 100644
--- a/platypush/backend/inotify/__init__.py
+++ b/platypush/backend/inotify/__init__.py
@@ -1,5 +1,4 @@
 import os
-import inotify.adapters
 
 from platypush.backend import Backend
 from platypush.message.event.path import PathCreateEvent, PathDeleteEvent, \
@@ -49,6 +48,7 @@ class InotifyBackend(Backend):
         self.inotify_watch = None
 
     def run(self):
+        import inotify.adapters
         super().run()
 
         self.inotify_watch = inotify.adapters.Inotify()
diff --git a/platypush/backend/joystick.py b/platypush/backend/joystick.py
index f3041492..b828ad4c 100644
--- a/platypush/backend/joystick.py
+++ b/platypush/backend/joystick.py
@@ -1,4 +1,3 @@
-import inputs
 import time
 
 from platypush.backend import Backend
@@ -30,6 +29,8 @@ class JoystickBackend(Backend):
         self.device = device
 
     def run(self):
+        import inputs
+
         super().run()
         self.logger.info('Initialized joystick backend on device {}'.format(self.device))
 
diff --git a/platypush/backend/kafka/__init__.py b/platypush/backend/kafka/__init__.py
index bce8b052..c74b66e1 100644
--- a/platypush/backend/kafka/__init__.py
+++ b/platypush/backend/kafka/__init__.py
@@ -2,8 +2,6 @@ import json
 import logging
 import time
 
-from kafka import KafkaConsumer, KafkaProducer
-
 from platypush.backend import Backend
 from platypush.context import get_plugin
 from platypush.message import Message
@@ -82,6 +80,7 @@ class KafkaBackend(Backend):
             self.logger.exception(e)
 
     def run(self):
+        from kafka import KafkaConsumer
         super().run()
 
         self.consumer = KafkaConsumer(self.topic, bootstrap_servers=self.server)
diff --git a/platypush/backend/nfc.py b/platypush/backend/nfc.py
index b3cd2dc0..c97aa1d3 100644
--- a/platypush/backend/nfc.py
+++ b/platypush/backend/nfc.py
@@ -1,7 +1,5 @@
 import base64
 import json
-import nfc
-import ndef
 
 from platypush.backend import Backend
 from platypush.message.event.nfc import NFCTagDetectedEvent, NFCTagRemovedEvent, NFCDeviceConnectedEvent, \
@@ -21,7 +19,8 @@ class NfcBackend(Backend):
 
     Requires:
 
-        * **nfcpy** >= 1.0 (``pip install nfcpy``)
+        * **nfcpy** >= 1.0 (``pip install 'nfcpy>=1.0'``)
+        * **ndef** (``pip install ndef``)
 
     Run the following to check if your device is compatible with nfcpy and the right permissions are set::
 
@@ -44,6 +43,8 @@ class NfcBackend(Backend):
         self._clf = None
 
     def _get_clf(self):
+        import nfc
+
         if not self._clf:
             self._clf = nfc.ContactlessFrontend()
             self._clf.open(self.device_id)
@@ -63,6 +64,7 @@ class NfcBackend(Backend):
 
     @staticmethod
     def _parse_records(tag):
+        import ndef
         records = []
 
         for record in tag.ndef.records:
diff --git a/platypush/backend/pushbullet/__init__.py b/platypush/backend/pushbullet/__init__.py
index e6e29d48..f0ddef8a 100644
--- a/platypush/backend/pushbullet/__init__.py
+++ b/platypush/backend/pushbullet/__init__.py
@@ -1,8 +1,6 @@
 import json
 import time
 
-from pushbullet import Pushbullet, Listener
-
 from platypush.backend import Backend
 from platypush.message.event.pushbullet import PushbulletEvent
 
@@ -43,6 +41,7 @@ class PushbulletBackend(Backend):
         :type proxy_port: int
         """
 
+        from pushbullet import Pushbullet
         super().__init__(**kwargs)
 
         self.token = token
@@ -133,6 +132,7 @@ class PushbulletBackend(Backend):
         return self.close()
 
     def run(self):
+        from pushbullet import Listener
         super().run()
 
         self.logger.info('Initialized Pushbullet backend - device_id: {}'
diff --git a/platypush/backend/scard/__init__.py b/platypush/backend/scard/__init__.py
index 2dcf231e..e1bec4fa 100644
--- a/platypush/backend/scard/__init__.py
+++ b/platypush/backend/scard/__init__.py
@@ -1,10 +1,5 @@
 import json
 
-from smartcard.CardType import AnyCardType, ATRCardType
-from smartcard.CardRequest import CardRequest
-from smartcard.Exceptions import NoCardException, CardConnectionException
-from smartcard.util import toHexString
-
 from platypush.backend import Backend
 from platypush.message.event.scard import SmartCardDetectedEvent, SmartCardRemovedEvent
 
@@ -32,6 +27,7 @@ class ScardBackend(Backend):
         :param atr: If set, the backend will trigger events only for card(s) with the specified ATR(s). It can be either an ATR string (space-separated hex octects) or a list of ATR strings.  Default: none (any card will be detected)
         """
 
+        from smartcard.CardType import AnyCardType, ATRCardType
         super().__init__(*args, **kwargs)
         self.ATRs = []
 
@@ -51,6 +47,10 @@ class ScardBackend(Backend):
 
 
     def run(self):
+        from smartcard.CardRequest import CardRequest
+        from smartcard.Exceptions import NoCardException, CardConnectionException
+        from smartcard.util import toHexString
+
         super().run()
 
         self.logger.info('Initialized smart card reader backend - ATR filter: {}'.
diff --git a/platypush/backend/wiimote.py b/platypush/backend/wiimote.py
index 31a7cd58..21961877 100644
--- a/platypush/backend/wiimote.py
+++ b/platypush/backend/wiimote.py
@@ -2,7 +2,6 @@
 .. moduleauthor:: Fabio Manganiello <blacklight86@gmail.com>
 """
 
-import cwiid
 import re
 import time
 
@@ -51,6 +50,8 @@ class WiimoteBackend(Backend):
 
 
     def get_wiimote(self):
+        import cwiid
+
         if not self._wiimote:
             if self._bdaddr:
                 self._wiimote = cwiid.Wiimote(bdaddr=self._bdaddr)
@@ -67,6 +68,7 @@ class WiimoteBackend(Backend):
         return self._wiimote
 
     def get_state(self):
+        import cwiid
         wm = self.get_wiimote()
         state = wm.state
         parsed_state = {}
diff --git a/platypush/plugins/adafruit/io.py b/platypush/plugins/adafruit/io.py
index 23a7009b..78ec1622 100644
--- a/platypush/plugins/adafruit/io.py
+++ b/platypush/plugins/adafruit/io.py
@@ -4,8 +4,6 @@ import json
 import time
 
 from threading import Thread, Lock
-from Adafruit_IO import Client
-from Adafruit_IO.errors import ThrottlingError
 
 from platypush.context import get_backend
 from platypush.plugins import Plugin, action
@@ -64,6 +62,7 @@ class AdafruitIoPlugin(Plugin):
         :type throttle_seconds: float
         """
 
+        from Adafruit_IO import Client
         global data_throttler_lock
         super().__init__(**kwargs)
 
diff --git a/platypush/plugins/assistant/echo/__init__.py b/platypush/plugins/assistant/echo/__init__.py
index 736ba31c..d474bd58 100644
--- a/platypush/plugins/assistant/echo/__init__.py
+++ b/platypush/plugins/assistant/echo/__init__.py
@@ -4,11 +4,6 @@
 
 import os
 
-from avs.auth import auth
-from avs.alexa import Alexa
-from avs.config import DEFAULT_CONFIG_FILE
-from avs.mic import Audio
-
 from platypush.context import get_bus
 from platypush.plugins import action
 from platypush.plugins.assistant import AssistantPlugin
@@ -43,7 +38,7 @@ class AssistantEchoPlugin(AssistantPlugin):
         * **avs** (``pip install avs``)
     """
 
-    def __init__(self, avs_config_file: str = DEFAULT_CONFIG_FILE, audio_device: str = 'default',
+    def __init__(self, avs_config_file: str = None, audio_device: str = 'default',
                  audio_player: str = 'default', **kwargs):
         """
         :param avs_config_file: AVS credentials file - default: ~/.avs.json. If the file doesn't exist then
@@ -55,9 +50,17 @@ class AssistantEchoPlugin(AssistantPlugin):
         :param audio_player: Player to be used for audio playback (default: 'default').
             Supported values: 'mpv', 'mpg123', 'gstreamer'
         """
+        from avs.alexa import Alexa
+        from avs.config import DEFAULT_CONFIG_FILE
+        from avs.mic import Audio
+
         super().__init__(**kwargs)
 
+        if not avs_config_file:
+            avs_config_file = DEFAULT_CONFIG_FILE
+
         if not avs_config_file or not os.path.isfile(avs_config_file):
+            from avs.auth import auth
             auth(None, avs_config_file)
             self.logger.warning('Amazon Echo assistant credentials not configured. Open http://localhost:3000 ' +
                                 'to authenticate this client')
diff --git a/platypush/plugins/assistant/google/pushtotalk.py b/platypush/plugins/assistant/google/pushtotalk.py
index 29959529..9ea709a4 100644
--- a/platypush/plugins/assistant/google/pushtotalk.py
+++ b/platypush/plugins/assistant/google/pushtotalk.py
@@ -5,9 +5,6 @@
 import json
 import os
 
-import googlesamples.assistant.grpc.audio_helpers as audio_helpers
-import googlesamples.assistant.grpc.device_helpers as device_helpers
-
 from platypush.context import get_bus
 from platypush.message.event.assistant import ConversationStartEvent, \
     ConversationEndEvent, SpeechRecognizedEvent, VolumeChangedEvent, \
@@ -17,7 +14,6 @@ from platypush.message.event.google import GoogleDeviceOnOffEvent
 
 from platypush.plugins import action
 from platypush.plugins.assistant import AssistantPlugin
-from platypush.plugins.assistant.google.lib import SampleAssistant
 
 
 class AssistantGooglePushtotalkPlugin(AssistantPlugin):
@@ -40,11 +36,6 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
     """
 
     api_endpoint = 'embeddedassistant.googleapis.com'
-    audio_sample_rate = audio_helpers.DEFAULT_AUDIO_SAMPLE_RATE
-    audio_sample_width = audio_helpers.DEFAULT_AUDIO_SAMPLE_WIDTH
-    audio_iter_size = audio_helpers.DEFAULT_AUDIO_ITER_SIZE
-    audio_block_size = audio_helpers.DEFAULT_AUDIO_DEVICE_BLOCK_SIZE
-    audio_flush_size = audio_helpers.DEFAULT_AUDIO_DEVICE_FLUSH_SIZE
     grpc_deadline = 60 * 3 + 5
     device_handler = None
 
@@ -79,8 +70,15 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
         :type play_response: bool
         """
 
+        import googlesamples.assistant.grpc.audio_helpers as audio_helpers
         super().__init__(**kwargs)
 
+        self.audio_sample_rate = audio_helpers.DEFAULT_AUDIO_SAMPLE_RATE
+        self.audio_sample_width = audio_helpers.DEFAULT_AUDIO_SAMPLE_WIDTH
+        self.audio_iter_size = audio_helpers.DEFAULT_AUDIO_ITER_SIZE
+        self.audio_block_size = audio_helpers.DEFAULT_AUDIO_DEVICE_BLOCK_SIZE
+        self.audio_flush_size = audio_helpers.DEFAULT_AUDIO_DEVICE_FLUSH_SIZE
+
         self.language = language
         self.credentials_file = credentials_file
         self.device_config = device_config
@@ -112,7 +110,9 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
         self.conversation_stream = None
 
     def _init_assistant(self):
+        import googlesamples.assistant.grpc.audio_helpers as audio_helpers
         from google.auth.transport.grpc import secure_authorized_channel
+
         self.interactions = []
 
         # Create an authorized gRPC channel.
@@ -217,6 +217,8 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
 
         """
 
+        from platypush.plugins.assistant.google.lib import SampleAssistant
+
         if not language:
             language = self.language
 
@@ -262,6 +264,7 @@ class AssistantGooglePushtotalkPlugin(AssistantPlugin):
             get_bus().post(ConversationEndEvent(assistant=self))
 
     def _install_device_handlers(self):
+        import googlesamples.assistant.grpc.device_helpers as device_helpers
         self.device_handler = device_helpers.DeviceRequestHandler(self.device_id)
 
         @self.device_handler.command('action.devices.commands.OnOff')
diff --git a/platypush/plugins/calendar/ical.py b/platypush/plugins/calendar/ical.py
index 459fb7b7..a7222508 100644
--- a/platypush/plugins/calendar/ical.py
+++ b/platypush/plugins/calendar/ical.py
@@ -6,8 +6,6 @@ import datetime
 import dateutil.parser
 import requests
 
-from icalendar import Calendar
-
 from platypush.plugins import Plugin, action
 from platypush.plugins.calendar import CalendarInterface
 
@@ -68,6 +66,7 @@ class CalendarIcalPlugin(Plugin, CalendarInterface):
         """
 
         import pytz
+        from icalendar import Calendar
 
         events = []
         try:
diff --git a/platypush/plugins/camera/ir/mlx90640/__init__.py b/platypush/plugins/camera/ir/mlx90640/__init__.py
index 16bb6411..0aa4215e 100644
--- a/platypush/plugins/camera/ir/mlx90640/__init__.py
+++ b/platypush/plugins/camera/ir/mlx90640/__init__.py
@@ -4,9 +4,6 @@ import os
 import subprocess
 import time
 
-# noinspection PyPackageRequirements
-from PIL import Image
-
 from platypush.plugins import Plugin, action
 
 
@@ -36,11 +33,7 @@ class CameraIrMlx90640Plugin(Plugin):
     """
 
     _img_size = (32, 24)
-    _rotate_values = {
-        90: Image.ROTATE_90,
-        180: Image.ROTATE_180,
-        270: Image.ROTATE_270,
-    }
+    _rotate_values = {}
 
     def __init__(self, fps=16, skip_frames=2, scale_factor=1, rotate=0, rawrgb_path=None, **kwargs):
         """
@@ -53,8 +46,15 @@ class CameraIrMlx90640Plugin(Plugin):
             https://github.com/pimoroni/mlx90640-library is in another folder than
             `<directory of this file>/lib/examples`.
         """
+        from PIL import Image
         super().__init__(**kwargs)
 
+        self._rotate_values = {
+            90: Image.ROTATE_90,
+            180: Image.ROTATE_180,
+            270: Image.ROTATE_270,
+        }
+
         if not rawrgb_path:
             rawrgb_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'lib', 'examples', 'rawrgb')
         rawrgb_path = os.path.abspath(os.path.expanduser(rawrgb_path))
@@ -121,6 +121,7 @@ class CameraIrMlx90640Plugin(Plugin):
             output_file is not set, otherwise a list with the captured image files will be returned.
         """
 
+        from PIL import Image
         fps = self.fps if fps is None else fps
         skip_frames = self.skip_frames if skip_frames is None else skip_frames
         scale_factor = self.scale_factor if scale_factor is None else scale_factor
@@ -170,6 +171,7 @@ class CameraIrMlx90640Plugin(Plugin):
 
     @staticmethod
     def _convert_to_grayscale(image):
+        from PIL import Image
         new_image = Image.new('L', image.size)
 
         for i in range(0, image.size[0]):
diff --git a/platypush/plugins/clipboard.py b/platypush/plugins/clipboard.py
index 593c28e9..e9fa4578 100644
--- a/platypush/plugins/clipboard.py
+++ b/platypush/plugins/clipboard.py
@@ -1,5 +1,3 @@
-import pyperclip
-
 from platypush.plugins import Plugin, action
 
 
@@ -20,6 +18,7 @@ class ClipboardPlugin(Plugin):
         :param text: Text to copy
         :type text: str
         """
+        import pyperclip
         pyperclip.copy(text)
 
 
@@ -28,6 +27,7 @@ class ClipboardPlugin(Plugin):
         """
         Get the current content of the clipboard
         """
+        import pyperclip
         return pyperclip.paste()
 
 
diff --git a/platypush/plugins/google/__init__.py b/platypush/plugins/google/__init__.py
index d340130b..d0c7834e 100644
--- a/platypush/plugins/google/__init__.py
+++ b/platypush/plugins/google/__init__.py
@@ -5,7 +5,6 @@
 import os
 
 from platypush.plugins import Plugin
-from platypush.plugins.google.credentials import get_credentials
 
 
 class GooglePlugin(Plugin):
@@ -41,6 +40,7 @@ class GooglePlugin(Plugin):
         :type scopes: list
         """
 
+        from platypush.plugins.google.credentials import get_credentials
         super().__init__(*args, **kwargs)
         self._scopes = scopes or []
 
diff --git a/platypush/plugins/google/mail.py b/platypush/plugins/google/mail.py
index 78d612b7..17ff27d0 100644
--- a/platypush/plugins/google/mail.py
+++ b/platypush/plugins/google/mail.py
@@ -7,8 +7,6 @@ import httplib2
 import mimetypes
 import os
 
-from apiclient import discovery
-
 from email.encoders import encode_base64
 from email.mime.application import MIMEApplication
 from email.mime.audio import MIMEAudio
diff --git a/platypush/plugins/gpio/sensor/envirophat.py b/platypush/plugins/gpio/sensor/envirophat.py
index f9b60e76..b4e0b5a2 100644
--- a/platypush/plugins/gpio/sensor/envirophat.py
+++ b/platypush/plugins/gpio/sensor/envirophat.py
@@ -1,5 +1,3 @@
-import envirophat
-
 from platypush.plugins import action
 from platypush.plugins.gpio.sensor import GpioSensorPlugin
 
@@ -46,6 +44,8 @@ class GpioSensorEnvirophatPlugin(GpioSensorPlugin):
 
         """
 
+        import envirophat
+
         ret = {}
         weather = envirophat.weather
         light = envirophat.light
diff --git a/platypush/plugins/gpio/sensor/motion/pwm3901.py b/platypush/plugins/gpio/sensor/motion/pwm3901.py
index fa190fad..25b08f3a 100644
--- a/platypush/plugins/gpio/sensor/motion/pwm3901.py
+++ b/platypush/plugins/gpio/sensor/motion/pwm3901.py
@@ -2,9 +2,6 @@ import enum
 import math
 import time
 
-# noinspection PyUnresolvedReferences,PyPackageRequirements
-from pmw3901 import PMW3901, BG_CS_FRONT_BCM, BG_CS_BACK_BCM
-
 from platypush.plugins import action
 from platypush.plugins.gpio.sensor import GpioSensorPlugin
 
@@ -43,7 +40,9 @@ class GpioSensorMotionPwm3901Plugin(GpioSensorPlugin):
         :param spi_port: SPI port (default: 0)
         :type spi_slot: int
         """
+        from pmw3901 import BG_CS_FRONT_BCM, BG_CS_BACK_BCM
         super().__init__(**kwargs)
+
         self.spi_port = spi_port
         self._sensor = None
         self._events_per_sec = {}
@@ -70,6 +69,8 @@ class GpioSensorMotionPwm3901Plugin(GpioSensorPlugin):
                 spi_slot, [s.value for s in SPISlot]))
 
     def _get_sensor(self):
+        from pmw3901 import PMW3901
+
         if not self._sensor:
             self._sensor = PMW3901(spi_port=self.spi_port,
                                    spi_cs=1,
diff --git a/platypush/plugins/http/request/rss.py b/platypush/plugins/http/request/rss.py
index 686b0ed2..498579a2 100644
--- a/platypush/plugins/http/request/rss.py
+++ b/platypush/plugins/http/request/rss.py
@@ -1,5 +1,3 @@
-import feedparser
-
 from platypush.plugins import action
 from platypush.plugins.http.request import HttpRequestPlugin
 
@@ -14,6 +12,7 @@ class HttpRequestRssPlugin(HttpRequestPlugin):
 
     @action
     def get(self, url):
+        import feedparser
         response = super().get(url, output='text').output
         feed = feedparser.parse(response)
         return feed.entries
diff --git a/platypush/plugins/kafka.py b/platypush/plugins/kafka.py
index d50bc03b..c0794fa6 100644
--- a/platypush/plugins/kafka.py
+++ b/platypush/plugins/kafka.py
@@ -2,8 +2,6 @@ import json
 import logging
 import time
 
-from kafka import KafkaProducer
-
 from platypush.context import get_backend
 from platypush.plugins import Plugin, action
 
@@ -47,6 +45,8 @@ class KafkaPlugin(Plugin):
         :type server: str
         """
 
+        from kafka import KafkaProducer
+
         if not server:
             if not self.server:
                 try:
diff --git a/platypush/plugins/lastfm/__init__.py b/platypush/plugins/lastfm/__init__.py
index 7c5565f6..1305cc27 100644
--- a/platypush/plugins/lastfm/__init__.py
+++ b/platypush/plugins/lastfm/__init__.py
@@ -1,4 +1,3 @@
-import pylast
 import time
 
 from platypush.plugins import Plugin, action
@@ -28,7 +27,9 @@ class LastfmPlugin(Plugin):
         :type api_key: str
         """
 
+        import pylast
         super().__init__()
+
         self.api_key = api_key
         self.api_secret = api_secret
         self.username = username
diff --git a/platypush/plugins/media/chromecast.py b/platypush/plugins/media/chromecast.py
index 38007340..20e2e9ca 100644
--- a/platypush/plugins/media/chromecast.py
+++ b/platypush/plugins/media/chromecast.py
@@ -1,10 +1,7 @@
 import datetime
 import re
-import pychromecast
 import time
 
-from pychromecast.controllers.youtube import YouTubeController
-
 from platypush.context import get_plugin, get_bus
 from platypush.plugins import action
 from platypush.plugins.media import MediaPlugin
@@ -151,6 +148,7 @@ class MediaChromecastPlugin(MediaPlugin):
         :type callback: func
         """
 
+        import pychromecast
         self.chromecasts.update({
             cast.device.friendly_name: cast
             for cast in pychromecast.get_chromecasts(tries=tries, retry_wait=retry_wait,
@@ -193,6 +191,7 @@ class MediaChromecastPlugin(MediaPlugin):
             cast.media_controller.register_status_listener(self._media_listeners[name])
 
     def get_chromecast(self, chromecast=None, n_tries=2):
+        import pychromecast
         if isinstance(chromecast, pychromecast.Chromecast):
             return chromecast
 
@@ -268,6 +267,7 @@ class MediaChromecastPlugin(MediaPlugin):
         :type subtitle_id: int
         """
 
+        from pychromecast.controllers.youtube import YouTubeController
         if not chromecast:
             chromecast = self.chromecast
 
diff --git a/platypush/plugins/media/plex.py b/platypush/plugins/media/plex.py
index 25c16797..7674846b 100644
--- a/platypush/plugins/media/plex.py
+++ b/platypush/plugins/media/plex.py
@@ -1,6 +1,3 @@
-from plexapi.myplex import MyPlexAccount
-from plexapi.video import Movie, Show
-
 from platypush.context import get_plugin
 from platypush.plugins import Plugin, action
 
@@ -26,6 +23,7 @@ class MediaPlexPlugin(Plugin):
         :type username: str
         """
 
+        from plexapi.myplex import MyPlexAccount
         super().__init__(*args, **kwargs)
 
         self.resource = MyPlexAccount(username, password).resource(server)
@@ -378,6 +376,8 @@ class MediaPlexPlugin(Plugin):
 
 
     def _flatten_item(self, item):
+        from plexapi.video import Movie, Show
+
         _item = {
             'summary': item.summary,
             'title': item.title,
diff --git a/platypush/plugins/midi.py b/platypush/plugins/midi.py
index ab9bba8a..a954050c 100644
--- a/platypush/plugins/midi.py
+++ b/platypush/plugins/midi.py
@@ -1,4 +1,3 @@
-import rtmidi
 import time
 
 from platypush.plugins import Plugin, action
@@ -23,6 +22,7 @@ class MidiPlugin(Plugin):
         :type device_name: str
         """
 
+        import rtmidi
         super().__init__(*args, **kwargs)
 
         self.device_name = device_name
@@ -126,6 +126,7 @@ class MidiPlugin(Plugin):
         :returns: dict: A list of the available MIDI ports with index and name
         """
 
+        import rtmidi
         in_ports = rtmidi.MidiIn().get_ports()
         out_ports = rtmidi.MidiOut().get_ports()
 
diff --git a/platypush/plugins/mqtt.py b/platypush/plugins/mqtt.py
index 01f880a8..e6a4e5cc 100644
--- a/platypush/plugins/mqtt.py
+++ b/platypush/plugins/mqtt.py
@@ -1,6 +1,5 @@
 import json
 import os
-import paho.mqtt.publish as publisher
 
 from platypush.message import Message
 from platypush.plugins import Plugin, action
@@ -105,6 +104,8 @@ class MqttPlugin(Plugin):
         :type password: str
         """
 
+        import paho.mqtt.publish as publisher
+
         if not host and not self.host:
             raise RuntimeError('No host specified and no default host configured')
 
diff --git a/platypush/plugins/music/mpd/__init__.py b/platypush/plugins/music/mpd/__init__.py
index c3601c9e..62763e68 100644
--- a/platypush/plugins/music/mpd/__init__.py
+++ b/platypush/plugins/music/mpd/__init__.py
@@ -1,4 +1,3 @@
-import mpd
 import re
 import threading
 import time
@@ -39,6 +38,8 @@ class MusicMpdPlugin(MusicPlugin):
         self.client = None
 
     def _connect(self, n_tries=2):
+        import mpd
+
         with self._client_lock:
             if self.client:
                 return
diff --git a/platypush/plugins/switch/switchbot/__init__.py b/platypush/plugins/switch/switchbot/__init__.py
index 078dc710..22c00ca2 100644
--- a/platypush/plugins/switch/switchbot/__init__.py
+++ b/platypush/plugins/switch/switchbot/__init__.py
@@ -2,8 +2,6 @@ import struct
 import subprocess
 import time
 
-from bluetooth.ble import DiscoveryService, GATTRequester
-
 from platypush.plugins import action
 from platypush.plugins.switch import SwitchPlugin
 
@@ -39,6 +37,7 @@ class Scanner(object):
         return uuids
 
     def scan(self):
+        from bluetooth.ble import DiscoveryService
         service = DiscoveryService(self.bt_interface) \
             if self.bt_interface else DiscoveryService()
 
@@ -62,6 +61,7 @@ class Driver(object):
         self.req = None
 
     def connect(self):
+        from bluetooth.ble import GATTRequester
         if self.bt_interface:
             self.req = GATTRequester(self.device, False, self.bt_interface)
         else:
diff --git a/platypush/plugins/switch/tplink.py b/platypush/plugins/switch/tplink.py
index 818a48ea..471cbfc2 100644
--- a/platypush/plugins/switch/tplink.py
+++ b/platypush/plugins/switch/tplink.py
@@ -1,5 +1,3 @@
-from pyHS100 import Discover
-
 from platypush.plugins import action
 from platypush.plugins.switch import SwitchPlugin
 
@@ -21,6 +19,8 @@ class SwitchTplinkPlugin(SwitchPlugin):
         super().__init__(**kwargs)
 
     def _scan(self):
+        from pyHS100 import Discover
+
         devices = Discover.discover()
         self._ip_to_dev = {}
         self._alias_to_dev = {}
diff --git a/platypush/plugins/tts/google.py b/platypush/plugins/tts/google.py
index db3b7ce0..9d76862e 100644
--- a/platypush/plugins/tts/google.py
+++ b/platypush/plugins/tts/google.py
@@ -2,8 +2,6 @@ import os
 import subprocess
 import tempfile
 
-from google.cloud import texttospeech
-
 from platypush.plugins import Plugin, action
 
 
@@ -35,7 +33,9 @@ class TtsGooglePlugin(Plugin):
         :type credentials_file: str
         """
 
+        from google.cloud import texttospeech
         super().__init__()
+
         self.language = language
         self.voice = voice
 
@@ -84,6 +84,7 @@ class TtsGooglePlugin(Plugin):
         :type gender: str
         """
 
+        from google.cloud import texttospeech
         client = texttospeech.TextToSpeechClient()
         synthesis_input = texttospeech.types.SynthesisInput(text=text)
 
@@ -120,4 +121,3 @@ class TtsGooglePlugin(Plugin):
 
 
 # vim:sw=4:ts=4:et:
-
diff --git a/requirements.txt b/requirements.txt
index 7fa9d0e8..4d96eca6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,7 @@ pyyaml
 # kafka-python
 
 # Pushbullet backend support
-git+https://github.com/rbrcsk/pushbullet.py
+# git+https://github.com/rbrcsk/pushbullet.py
 
 # HTTP backend support
 flask
@@ -181,3 +181,6 @@ croniter
 
 # Support for Alexa/Echo voice integrations
 # git+https://github.com:BlackLight/avs.git
+
+# Support for clipboard manipulation
+# pyperclip
diff --git a/setup.py b/setup.py
index f3a778fc..2d3eac6d 100755
--- a/setup.py
+++ b/setup.py
@@ -145,9 +145,9 @@ setup(
         # Support for Pushbullet backend and plugin
         'pushbullet': ['pushbullet.py'],
         # Support for HTTP backend
-        'http': ['flask','websockets', 'python-dateutil', 'tz', 'frozendict', 'bcrypt', 'sqlalchemy'],
+        'http': ['flask', 'websockets', 'python-dateutil', 'tz', 'frozendict', 'bcrypt', 'sqlalchemy'],
         # Support for uWSGI HTTP backend
-        'uwsgi': ['flask','websockets', 'python-dateutil', 'tz', 'frozendict', 'uwsgi', 'bcrypt', 'sqlalchemy'],
+        'uwsgi': ['flask', 'websockets', 'python-dateutil', 'tz', 'frozendict', 'uwsgi', 'bcrypt', 'sqlalchemy'],
         # Support for database
         'db': ['sqlalchemy'],
         # Support for MQTT backends