Fix a couple of inconsistencies in the public interface (#1102)

* Create `_NOT_A_REQUEST` when needed. Currently, modifications    
  in the raised exception would be "global".    
* `retries` parameters were actually attempts. This has been fixed    
  to actually be the amount of retries, so 0 now means don't retry.    
* Helper function to deal with retries instead of using a range with    
  different styles every time.

telethon/client/account.py

@@ -53,7 +53,7 @@ class _TakeoutClient:
         wrapped = []
         for r in requests:
             if not isinstance(r, TLRequest):
-                raise _NOT_A_REQUEST
+                raise _NOT_A_REQUEST()
             await r.resolve(self, utils)
             wrapped.append(functions.InvokeWithTakeoutRequest(takeout_id, r))
 

telethon/client/telegrambaseclient.py

@@ -71,23 +71,23 @@ class TelegramBaseClient(abc.ABC):
             invoked requests, and you should use ``asyncio.wait`` or
             ``asyncio.wait_for`` for that.
 
-        request_retries (`int`, optional):
+        request_retries (`int` | `None`, optional):
             How many times a request should be retried. Request are retried
             when Telegram is having internal issues (due to either
             ``errors.ServerError`` or ``errors.RpcCallFailError``),
             when there is a ``errors.FloodWaitError`` less than
             `flood_sleep_threshold`, or when there's a migrate error.
 
-            May set to a false-y value (``0`` or ``None``) for infinite
-            retries, but this is not recommended, since some requests can
-            always trigger a call fail (such as searching for messages).
+            May take a negative or ``None`` value for infinite retries, but
+            this is not recommended, since some requests can always trigger
+            a call fail (such as searching for messages).
 
-        connection_retries (`int`, optional):
+        connection_retries (`int` | `None`, optional):
             How many times the reconnection should retry, either on the
             initial connection or when Telegram disconnects us. May be
-            set to a false-y value (``0`` or ``None``) for infinite
-            retries, but this is not recommended, since the program can
-            get stuck in an infinite loop.
+            set to a negative or ``None`` value for infinite retries, but
+            this is not recommended, since the program can get stuck in an
+            infinite loop.
 
         retry_delay (`int` | `float`, optional):
             The delay in seconds to sleep between automatic reconnections.
@@ -236,8 +236,8 @@ class TelegramBaseClient(abc.ABC):
         self.api_id = int(api_id)
         self.api_hash = api_hash
 
-        self._request_retries = request_retries or sys.maxsize
-        self._connection_retries = connection_retries or sys.maxsize
+        self._request_retries = request_retries
+        self._connection_retries = connection_retries
         self._retry_delay = retry_delay or 0
         self._proxy = proxy
         self._timeout = timeout

telethon/client/users.py

@@ -6,8 +6,9 @@ from .telegrambaseclient import TelegramBaseClient
 from .. import errors, utils
 from ..errors import MultiError, RPCError
 from ..tl import TLObject, TLRequest, types, functions
+from ..helpers import retry_range
 
-_NOT_A_REQUEST = TypeError('You can only invoke requests, not types!')
+_NOT_A_REQUEST = lambda: TypeError('You can only invoke requests, not types!')
 
 
 class UserMethods(TelegramBaseClient):
@@ -15,7 +16,7 @@ class UserMethods(TelegramBaseClient):
         requests = (request if utils.is_list_like(request) else (request,))
         for r in requests:
             if not isinstance(r, TLRequest):
-                raise _NOT_A_REQUEST
+                raise _NOT_A_REQUEST()
             await r.resolve(self, utils)
 
             # Avoid making the request if it's already in a flood wait
@@ -34,7 +35,7 @@ class UserMethods(TelegramBaseClient):
 
         request_index = 0
         self._last_request = time.time()
-        for _ in range(self._request_retries):
+        for attempt in retry_range(self._request_retries):
             try:
                 future = self._sender.send(request, ordered=ordered)
                 if isinstance(future, list):
@@ -86,7 +87,8 @@ class UserMethods(TelegramBaseClient):
                     raise
                 await self._switch_dc(e.new_dc)
 
-        raise ValueError('Number of retries reached 0')
+        raise ValueError('Request was unsuccessful {} time(s)'
+                         .format(attempt))
 
     # region Public methods