Revert dropping Python 3.5 support

.travis.yml

@@ -45,7 +45,7 @@ stage_linux: &stage_linux
   <<: *stage_generic
   os: linux
   language: python
-  python: 3.6
+  python: 3.5
 
 stage_osx: &stage_osx
   <<: *stage_generic
@@ -82,6 +82,9 @@ stage_win: &stage_win
     |
     export PATH="/c/Python${PYTHON_VERSION}:/c/Python${PYTHON_VERSION}/Scripts:${PATH}"
     case $PYTHON_VERSION in
+      35)
+        choco install python --version 3.5.4
+        ;;
       36)
         choco install python --version 3.6.5
         ;;
@@ -112,7 +115,7 @@ jobs:
   include:
     # "lint and and pure python test" stage
     ###########################################################################
-    # Linter and style check (GNU/Linux, Python 3.7)
+    # Linter and style check (GNU/Linux, Python 3.5)
     - stage: lint and pure python test
       <<: *stage_linux
       if: type != cron
@@ -126,7 +129,7 @@ jobs:
       if: type != cron
       script: make mypy
 
-    # Run the tests against without compilation (GNU/Linux, Python 3.6)
+    # Run the tests against without compilation (GNU/Linux, Python 3.5)
     - stage: lint and pure python test
       <<: *stage_linux
       if: type != cron
@@ -153,6 +156,14 @@ jobs:
       dist: xenial
       python: 3.8
 
+    # OSX, Python 3.5.6 (via pyenv)
+    - stage: test
+      <<: *stage_osx
+      if: type != cron
+      env:
+        - MPLBACKEND=ps
+        - PYTHON_VERSION=3.5.6
+
     # OSX, Python 3.6.5 (via pyenv)
     - stage: test
       <<: *stage_osx
@@ -217,6 +228,11 @@ jobs:
       <<: *stage_win
       env:
         - PYTHON_VERSION=36
+    # Windows, Python 3.5
+    - if: type = cron
+      <<: *stage_win
+      env:
+        - PYTHON_VERSION=35
     - if: tag IS present
       language: python
       python: "3.6"

Makefile

@@ -17,7 +17,7 @@ lint:
 	pylint -rn qiskit/providers/ibmq test
 
 mypy:
-	mypy --module qiskit.providers.ibmq --show-error-codes --no-site-packages
+	mypy --module qiskit.providers.ibmq --show-error-codes
 
 style:
 	pycodestyle qiskit test

azure-pipelines.yml

@@ -13,6 +13,8 @@ jobs:
 #  condition: eq(variables['Build.Reason'], 'PullRequest')
   strategy:
     matrix:
+      Python35:
+        python.version: '3.5'
       Python36:
         python.version: '3.6'
       Python37:
@@ -42,8 +44,10 @@ jobs:
   condition: eq(variables['Build.Reason'], 'Schedule')
   strategy:
     matrix:
-      Python36:
-        python.version: '3.6'
+      Python35:
+        python.version: '3.5'
+#      Python36:
+#        python.version: '3.6'
 #      Python37:
 #        python.version: '3.7'
   steps:

qiskit/providers/ibmq/accountprovider.py

@@ -142,12 +142,10 @@ def _discover_remote_backends(self, timeout: Optional[float] = None) -> Dict[str
 
         return ret
 
-    def __eq__(
+    def __eq__(  # type: ignore[override]
             self,
-            other: Any
+            other: 'AccountProvider'
     ) -> bool:
-        if not isinstance(other, AccountProvider):
-            return False
         return self.credentials == other.credentials
 
     def __repr__(self) -> str:

qiskit/providers/ibmq/api/clients/account.py

@@ -19,7 +19,8 @@
 import time
 
 from typing import List, Dict, Any, Optional, Union
-from datetime import datetime
+# Disabled unused-import because datetime is used only for type hints.
+from datetime import datetime  # pylint: disable=unused-import
 
 from qiskit.providers.ibmq.apiconstants import (API_JOB_FINAL_STATES, ApiJobStatus,
                                                 ApiJobShareLevel)

qiskit/providers/ibmq/api/clients/auth.py

@@ -14,7 +14,7 @@
 
 """Client for accessing IBM Quantum Experience authentication services."""
 
-from typing import Dict, List, Optional, Any, Union
+from typing import Dict, List, Optional, Any
 from requests.exceptions import RequestException
 
 from ..exceptions import AuthenticationLicenseError, RequestsApiError
@@ -140,7 +140,7 @@ def user_hubs(self) -> List[Dict[str, str]]:
 
     # Miscellaneous public functions.
 
-    def api_version(self) -> Dict[str, Union[str, bool]]:
+    def api_version(self) -> Dict[str, str]:
         """Return the version of the API.
 
         Returns:

qiskit/providers/ibmq/api/clients/websocket.py

@@ -20,7 +20,7 @@
 import logging
 import time
 from abc import ABC, abstractmethod
-from typing import Dict, Union, Optional, Any
+from typing import Dict, Union, Generator, Optional, Any
 from concurrent import futures
 from ssl import SSLError
 import warnings
@@ -57,6 +57,10 @@
 except RuntimeError:
     LOOP = asyncio.new_event_loop()
 nest_asyncio.apply(LOOP)
+# TODO Replace coroutine with async def once Python 3.5 is dropped.
+# Also can upgrade to websocket 8 to avoid other deprecation warning.
+warnings.filterwarnings("ignore", category=DeprecationWarning,
+                        message="\"@coroutine\" decorator is deprecated")
 
 
 class WebsocketMessage(ABC):
@@ -147,7 +151,8 @@ def __init__(self, websocket_url: str, access_token: str) -> None:
         self.websocket_url = websocket_url.rstrip('/')
         self.access_token = access_token
 
-    async def _connect(self, url: str) -> WebSocketClientProtocol:
+    @asyncio.coroutine
+    def _connect(self, url: str) -> Generator[Any, None, WebSocketClientProtocol]:
         """Authenticate with the websocket server and return the connection.
 
         Returns:
@@ -164,7 +169,9 @@ async def _connect(self, url: str) -> WebSocketClientProtocol:
         try:
             logger.debug('Starting new websocket connection: %s', url)
             with warnings.catch_warnings():
-                websocket = await connect(url)
+                # Suppress websockets deprecation warnings until the fix is available
+                warnings.filterwarnings("ignore", category=DeprecationWarning)
+                websocket = yield from connect(url)
 
         # Isolate specific exceptions, so they are not retried in `get_job_status`.
         except (SSLError, InvalidURI) as ex:
@@ -182,19 +189,20 @@ async def _connect(self, url: str) -> WebSocketClientProtocol:
             # Authenticate against the server.
             auth_request = self._authentication_message()
             with warnings.catch_warnings():
-                await websocket.send(auth_request.as_json())
+                # Suppress websockets deprecation warnings until the fix is available
+                warnings.filterwarnings("ignore", category=DeprecationWarning)
+                yield from websocket.send(auth_request.as_json())
 
                 # Verify that the server acknowledged our authentication.
-                auth_response_raw = await websocket.recv()
+                auth_response_raw = yield from websocket.recv()
 
-            auth_response = WebsocketResponseMethod.from_bytes(
-                auth_response_raw)  # type: ignore[arg-type]
+            auth_response = WebsocketResponseMethod.from_bytes(auth_response_raw)
 
             if auth_response.type_ != 'authenticated':
                 raise WebsocketIBMQProtocolError('Failed to authenticate against the server: {}'
                                                  .format(auth_response.as_json()))
         except ConnectionClosed as ex:
-            await websocket.close()
+            yield from websocket.close()
             exception_to_raise = WebsocketAuthenticationError(
                 'Unexpected error occurred when authenticating against the server.')
 
@@ -204,14 +212,15 @@ async def _connect(self, url: str) -> WebSocketClientProtocol:
 
         return websocket
 
-    async def get_job_status(
+    @asyncio.coroutine
+    def get_job_status(
             self,
             job_id: str,
             timeout: Optional[float] = None,
             retries: int = 5,
             backoff_factor: float = 0.5,
             status_queue: Optional[RefreshQueue] = None
-    ) -> Dict[str, str]:
+    ) -> Generator[Any, None, Dict[str, str]]:
         """Return the status of a job.
 
         Read status messages from the server, which are issued at regular
@@ -260,23 +269,24 @@ async def get_job_status(
 
         while current_retry_attempt <= retries:
             try:
-                websocket = await self._connect(url)
+                websocket = yield from self._connect(url)
                 # Read messages from the server until the connection is closed or
                 # a timeout has been reached.
                 while True:
                     try:
                         with warnings.catch_warnings():
+                            # Suppress websockets deprecation warnings until the fix is available
+                            warnings.filterwarnings("ignore", category=DeprecationWarning)
                             if timeout:
-                                response_raw = await asyncio.wait_for(
+                                response_raw = yield from asyncio.wait_for(
                                     websocket.recv(), timeout=timeout)
 
                                 # Decrease the timeout.
                                 timeout = original_timeout - (time.time() - start_time)
                             else:
-                                response_raw = await websocket.recv()
+                                response_raw = yield from websocket.recv()
 
-                        response = WebsocketResponseMethod.from_bytes(
-                            response_raw)  # type: ignore[arg-type]
+                        response = WebsocketResponseMethod.from_bytes(response_raw)
                         if logger.getEffectiveLevel() is logging.DEBUG:
                             logger.debug('Received message from websocket: %s',
                                          filter_data(response.get_data()))
@@ -346,14 +356,16 @@ async def get_job_status(
                 backoff_time = self._backoff_time(backoff_factor, current_retry_attempt)
                 logger.info('Retrying get_job_status via websocket after %s seconds: '
                             'Attempt #%s', backoff_time, current_retry_attempt)
-                await asyncio.sleep(backoff_time)  # Block asyncio loop for given backoff time.
+                yield from asyncio.sleep(backoff_time)  # Block asyncio loop for given backoff time.
 
                 continue  # Continues next iteration after `finally` block.
 
             finally:
                 with warnings.catch_warnings():
+                    # Suppress websockets deprecation warnings until the fix is available
+                    warnings.filterwarnings("ignore", category=DeprecationWarning)
                     if websocket is not None:
-                        await websocket.close()
+                        yield from websocket.close()
 
         # Execution should not reach here, sanity check.
         exception_message = 'Max retries exceeded: Failed to establish a websocket ' \

qiskit/providers/ibmq/api/rest/backend.py

@@ -16,7 +16,7 @@
 
 import json
 from typing import Dict, Optional, Any, List
-from datetime import datetime
+from datetime import datetime  # pylint: disable=unused-import
 
 from .base import RestAdapterBase
 from ..session import RetrySession

qiskit/providers/ibmq/backendjoblimit.py

@@ -14,7 +14,7 @@
 
 """Job limit information related to a backend."""
 
-from typing import Any, Dict
+from typing import Any
 
 
 class BackendJobLimit:
@@ -31,7 +31,7 @@ class BackendJobLimit:
             this provider.
     """
 
-    _data = {}  # type:Dict
+    _data = {}
 
     def __init__(self, maximum_jobs: int, running_jobs: int, **kwargs: Any) -> None:
         """BackendJobLimit constructor.

qiskit/providers/ibmq/backendreservation.py

@@ -14,7 +14,7 @@
 
 """Reservation information related to a backend."""
 
-from typing import Optional, Any
+from typing import Optional
 from datetime import datetime
 
 
@@ -87,7 +87,7 @@ def __repr__(self) -> str:
         out_str += ')>'
         return out_str
 
-    def __eq__(self, other: Any) -> bool:
+    def __eq__(self, other):
         if isinstance(other, BackendReservation) and self.backend_name == other.backend_name:
             if self.reservation_id and self.reservation_id == other.reservation_id:
                 return True

qiskit/providers/ibmq/ibmqbackendservice.py

@@ -21,8 +21,7 @@
 from typing import Dict, List, Callable, Optional, Any, Union
 from datetime import datetime
 
-from qiskit.providers.jobstatus import JobStatus
-from qiskit.providers.exceptions import QiskitBackendNotFoundError
+from qiskit.providers import JobStatus, QiskitBackendNotFoundError  # type: ignore[attr-defined]
 from qiskit.providers.providerutils import filter_backends
 from qiskit.providers.ibmq import accountprovider  # pylint: disable=unused-import
 
@@ -360,13 +359,13 @@ def _update_creation_date_filter(
                 lt_list.append(cur_dt_filter.pop('between')[1])
             lte_dt = min(lt_list) if lt_list else None
 
-        new_dt_filter = {}  # type: Dict[str, Union[str, List[str]]]
+        new_dt_filter = {}
         if gte_dt and lte_dt:
             new_dt_filter['between'] = [gte_dt, lte_dt]
         elif gte_dt:
-            new_dt_filter['gte'] = gte_dt
+            new_dt_filter['gte'] = gte_dt  # type: ignore[assignment]
         elif lte_dt:
-            new_dt_filter['lte'] = lte_dt
+            new_dt_filter['lte'] = lte_dt  # type: ignore[assignment]
 
         return new_dt_filter
 
@@ -432,7 +431,7 @@ def _get_status_filter(self, status: Union[JobStatus, str]) -> Dict[str, Any]:
         elif status == JobStatus.DONE:
             _status_filter = {'status': ApiJobStatus.COMPLETED.value}
         elif status == JobStatus.ERROR:
-            _status_filter = {'status': {'regexp': '^ERROR'}}
+            _status_filter = {'status': {'regexp': '^ERROR'}}  # type: ignore[assignment]
         else:
             raise IBMQBackendValueError(
                 '"{}" is not a valid status value. Valid values are {}'.format(

qiskit/providers/ibmq/job/ibmqjob.py

@@ -98,7 +98,7 @@ class IBMQJob(BaseJob):
     which is a supported attribute.
     """
 
-    _data = {}  # type: Dict
+    _data = {}
 
     _executor = futures.ThreadPoolExecutor()
     """Threads used for asynchronous processing."""
@@ -890,7 +890,7 @@ def _wait_for_completion(
 
         return self._status in required_status
 
-    def _retrieve_result(self, refresh: bool = False) -> None:
+    def _retrieve_result(self, refresh: bool = False):
         """Retrieve the job result response.
 
         Args:

qiskit/providers/ibmq/job/queueinfo.py

@@ -14,7 +14,7 @@
 
 """Queue information for a job."""
 
-from typing import Any, Optional, Union, Dict
+from typing import Any, Optional, Union
 from datetime import datetime
 import warnings
 
@@ -27,7 +27,7 @@
 class QueueInfo:
     """Queue information for a job."""
 
-    _data = {}  # type: Dict
+    _data = {}
 
     def __init__(
             self,