From ea39062d2d1c2f4d9ade1ac237962879bee5efb1 Mon Sep 17 00:00:00 2001
From: Dan <14043624+delivrance@users.noreply.github.com>
Date: Sat, 8 Sep 2018 19:16:51 +0200
Subject: [PATCH] Add get_chat_members_count method

---
 pyrogram/client/methods/chats/__init__.py     |  4 +-
 .../methods/chats/get_chat_members_count.py   | 53 +++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 pyrogram/client/methods/chats/get_chat_members_count.py

diff --git a/pyrogram/client/methods/chats/__init__.py b/pyrogram/client/methods/chats/__init__.py
index 72134abf..f9eb25f3 100644
--- a/pyrogram/client/methods/chats/__init__.py
+++ b/pyrogram/client/methods/chats/__init__.py
@@ -21,6 +21,7 @@ from .export_chat_invite_link import ExportChatInviteLink
 from .get_chat import GetChat
 from .get_chat_member import GetChatMember
 from .get_chat_members import GetChatMembers
+from .get_chat_members_count import GetChatMembersCount
 from .get_dialogs import GetDialogs
 from .join_chat import JoinChat
 from .kick_chat_member import KickChatMember
@@ -52,6 +53,7 @@ class Chats(
     SetChatDescription,
     PinChatMessage,
     UnpinChatMessage,
-    GetDialogs
+    GetDialogs,
+    GetChatMembersCount
 ):
     pass
diff --git a/pyrogram/client/methods/chats/get_chat_members_count.py b/pyrogram/client/methods/chats/get_chat_members_count.py
new file mode 100644
index 00000000..efe53c19
--- /dev/null
+++ b/pyrogram/client/methods/chats/get_chat_members_count.py
@@ -0,0 +1,53 @@
+# Pyrogram - Telegram MTProto API Client Library for Python
+# Copyright (C) 2017-2018 Dan Tès <https://github.com/delivrance>
+#
+# This file is part of Pyrogram.
+#
+# Pyrogram is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published
+# by the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Pyrogram is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Pyrogram.  If not, see <http://www.gnu.org/licenses/>.
+
+from pyrogram.api import functions, types
+from ...ext import BaseClient
+
+
+class GetChatMembersCount(BaseClient):
+    def get_chat_members_count(self, chat_id: int or str):
+        """Use this method to get the number of members in a chat.
+
+        Args:
+            chat_id (``int`` | ``str``):
+                Unique identifier (int) or username (str) of the target chat.
+
+        Returns:
+            On success, an integer is returned.
+
+        Raises:
+            :class:`Error <pyrogram.Error>
+            ``ValueError``: If a chat_id belongs to user.
+        """
+        peer = self.resolve_peer(chat_id)
+
+        if isinstance(peer, types.InputPeerChat):
+            return self.send(
+                functions.messages.GetChats(
+                    id=[peer.chat_id]
+                )
+            ).chats[0].participants_count
+        elif isinstance(peer, types.InputPeerChannel):
+            return self.send(
+                functions.channels.GetFullChannel(
+                    channel=peer
+                )
+            ).full_chat.participants_count
+        else:
+            raise ValueError("The chat_id \"{}\" belongs to a user".format(chat_id))