import datetime import io import os import pathlib import typing import inspect import asyncio from ..crypto import AES from .. import utils, helpers, errors, hints from ..requestiter import RequestIter from ..tl import TLObject, types, functions try: import aiohttp except ImportError: aiohttp = None if typing.TYPE_CHECKING: from .telegramclient import TelegramClient # Chunk sizes for upload.getFile must be multiples of the smallest size MIN_CHUNK_SIZE = 4096 MAX_CHUNK_SIZE = 512 * 1024 # 2021-01-15, users reported that `errors.TimeoutError` can occur while downloading files. TIMED_OUT_SLEEP = 1 class _DirectDownloadIter(RequestIter): async def _init( self, file, dc_id, offset, stride, chunk_size, request_size, file_size, msg_data ): self.request = functions.upload.GetFileRequest( file, offset=offset, limit=request_size) self.total = file_size self._stride = stride self._chunk_size = chunk_size self._last_part = None self._msg_data = msg_data self._timed_out = False self._exported = dc_id and self.client.session.dc_id != dc_id if not self._exported: # The used sender will also change if ``FileMigrateError`` occurs self._sender = self.client._sender else: try: self._sender = await self.client._borrow_exported_sender(dc_id) except errors.DcIdInvalidError: # Can't export a sender for the ID we are currently in config = await self.client(functions.help.GetConfigRequest()) for option in config.dc_options: if option.ip_address == self.client.session.server_address: self.client.session.set_dc( option.id, option.ip_address, option.port) self.client.session.save() break # TODO Figure out why the session may have the wrong DC ID self._sender = self.client._sender self._exported = False async def _load_next_chunk(self): cur = await self._request() self.buffer.append(cur) if len(cur) < self.request.limit: self.left = len(self.buffer) await self.close() else: self.request.offset += self._stride async def _request(self): try: result = await self.client._call(self._sender, self.request) self._timed_out = False if isinstance(result, types.upload.FileCdnRedirect): raise NotImplementedError # TODO Implement else: return result.bytes except errors.TimeoutError as e: if self._timed_out: self.client._log[__name__].warning('Got two timeouts in a row while downloading file') raise self._timed_out = True self.client._log[__name__].info('Got timeout while downloading file, retrying once') await asyncio.sleep(TIMED_OUT_SLEEP) return await self._request() except errors.FileMigrateError as e: self.client._log[__name__].info('File lives in another DC') self._sender = await self.client._borrow_exported_sender(e.new_dc) self._exported = True return await self._request() except errors.FilerefUpgradeNeededError as e: # Only implemented for documents which are the ones that may take that long to download if not self._msg_data \ or not isinstance(self.request.location, types.InputDocumentFileLocation) \ or self.request.location.thumb_size != '': raise self.client._log[__name__].info('File ref expired during download; refetching message') chat, msg_id = self._msg_data msg = await self.client.get_messages(chat, ids=msg_id) if not isinstance(msg.media, types.MessageMediaDocument): raise document = msg.media.document # Message media may have been edited for something else if document.id != self.request.location.id: raise self.request.location.file_reference = document.file_reference return await self._request() async def close(self): if not self._sender: return try: if self._exported: await self.client._return_exported_sender(self._sender) elif self._sender != self.client._sender: await self._sender.disconnect() finally: self._sender = None async def __aenter__(self): return self async def __aexit__(self, *args): await self.close() class _GenericDownloadIter(_DirectDownloadIter): async def _load_next_chunk(self): # 1. Fetch enough for one chunk data = b'' # 1.1. ``bad`` is how much into the data we have we need to offset bad = self.request.offset % self.request.limit before = self.request.offset # 1.2. We have to fetch from a valid offset, so remove that bad part self.request.offset -= bad done = False while not done and len(data) - bad < self._chunk_size: cur = await self._request() self.request.offset += self.request.limit data += cur done = len(cur) < self.request.limit # 1.3 Restore our last desired offset self.request.offset = before # 2. Fill the buffer with the data we have # 2.1. Slicing `bytes` is expensive, yield `memoryview` instead mem = memoryview(data) # 2.2. The current chunk starts at ``bad`` offset into the data, # and each new chunk is ``stride`` bytes apart of the other for i in range(bad, len(data), self._stride): self.buffer.append(mem[i:i + self._chunk_size]) # 2.3. We will yield this offset, so move to the next one self.request.offset += self._stride # 2.4. If we are in the last chunk, we will return the last partial data if done: self.left = len(self.buffer) await self.close() return # 2.5. If we are not done, we can't return incomplete chunks. if len(self.buffer[-1]) != self._chunk_size: self._last_part = self.buffer.pop().tobytes() # 3. Be careful with the offsets. Re-fetching a bit of data # is fine, since it greatly simplifies things. # TODO Try to not re-fetch data self.request.offset -= self._stride async def download_profile_photo( self: 'TelegramClient', entity: 'hints.EntityLike', file: 'hints.FileLike' = None, *, download_big: bool = True) -> typing.Optional[str]: """ Downloads the profile photo from the given user, chat or channel. Arguments entity (`entity`): From who the photo will be downloaded. .. note:: This method expects the full entity (which has the data to download the photo), not an input variant. It's possible that sometimes you can't fetch the entity from its input (since you can get errors like ``ChannelPrivateError``) but you already have it through another call, like getting a forwarded message from it. file (`str` | `file`, optional): The output file path, directory, or stream-like object. If the path exists and is a file, it will be overwritten. If file is the type `bytes`, it will be downloaded in-memory as a bytestring (e.g. ``file=bytes``). download_big (`bool`, optional): Whether to use the big version of the available photos. Returns `None` if no photo was provided, or if it was Empty. On success the file path is returned since it may differ from the one given. Example .. code-block:: python # Download your own profile photo path = await client.download_profile_photo('me') print(path) """ # hex(crc32(x.encode('ascii'))) for x in # ('User', 'Chat', 'UserFull', 'ChatFull') ENTITIES = (0x2da17977, 0xc5af5d94, 0x1f4661b9, 0xd49a2697) # ('InputPeer', 'InputUser', 'InputChannel') INPUTS = (0xc91c90b6, 0xe669bf46, 0x40f202fd) if not isinstance(entity, TLObject) or entity.SUBCLASS_OF_ID in INPUTS: entity = await self.get_entity(entity) thumb = -1 if download_big else 0 possible_names = [] if entity.SUBCLASS_OF_ID not in ENTITIES: photo = entity else: if not hasattr(entity, 'photo'): # Special case: may be a ChatFull with photo:Photo # This is different from a normal UserProfilePhoto and Chat if not hasattr(entity, 'chat_photo'): return None return await self._download_photo( entity.chat_photo, file, date=None, thumb=thumb, progress_callback=None ) for attr in ('username', 'first_name', 'title'): possible_names.append(getattr(entity, attr, None)) photo = entity.photo if isinstance(photo, (types.UserProfilePhoto, types.ChatPhoto)): dc_id = photo.dc_id loc = types.InputPeerPhotoFileLocation( peer=await self.get_input_entity(entity), photo_id=photo.photo_id, big=download_big ) else: # It doesn't make any sense to check if `photo` can be used # as input location, because then this method would be able # to "download the profile photo of a message", i.e. its # media which should be done with `download_media` instead. return None file = self._get_proper_filename( file, 'profile_photo', '.jpg', possible_names=possible_names ) try: result = await self.download_file(loc, file, dc_id=dc_id) return result if file is bytes else file except errors.LocationInvalidError: # See issue #500, Android app fails as of v4.6.0 (1155). # The fix seems to be using the full channel chat photo. ie = await self.get_input_entity(entity) ty = helpers._entity_type(ie) if ty == helpers._EntityType.CHANNEL: full = await self(functions.channels.GetFullChannelRequest(ie)) return await self._download_photo( full.full_chat.chat_photo, file, date=None, progress_callback=None, thumb=thumb ) else: # Until there's a report for chats, no need to. return None async def download_media( self: 'TelegramClient', message: 'hints.MessageLike', file: 'hints.FileLike' = None, *, thumb: 'typing.Union[int, types.TypePhotoSize]' = None, progress_callback: 'hints.ProgressCallback' = None) -> typing.Optional[typing.Union[str, bytes]]: """ Downloads the given media from a message object. Note that if the download is too slow, you should consider installing ``cryptg`` (through ``pip install cryptg``) so that decrypting the received data is done in C instead of Python (much faster). See also `Message.download_media() `. Arguments message (`Message ` | :tl:`Media`): The media or message containing the media that will be downloaded. file (`str` | `file`, optional): The output file path, directory, or stream-like object. If the path exists and is a file, it will be overwritten. If file is the type `bytes`, it will be downloaded in-memory as a bytestring (e.g. ``file=bytes``). progress_callback (`callable`, optional): A callback function accepting two parameters: ``(received bytes, total)``. thumb (`int` | :tl:`PhotoSize`, optional): Which thumbnail size from the document or photo to download, instead of downloading the document or photo itself. If it's specified but the file does not have a thumbnail, this method will return `None`. The parameter should be an integer index between ``0`` and ``len(sizes)``. ``0`` will download the smallest thumbnail, and ``len(sizes) - 1`` will download the largest thumbnail. You can also use negative indices, which work the same as they do in Python's `list`. You can also pass the :tl:`PhotoSize` instance to use. Alternatively, the thumb size type `str` may be used. In short, use ``thumb=0`` if you want the smallest thumbnail and ``thumb=-1`` if you want the largest thumbnail. .. note:: The largest thumbnail may be a video instead of a photo, as they are available since layer 116 and are bigger than any of the photos. Returns `None` if no media was provided, or if it was Empty. On success the file path is returned since it may differ from the one given. Example .. code-block:: python path = await client.download_media(message) await client.download_media(message, filename) # or path = await message.download_media() await message.download_media(filename) # Printing download progress def callback(current, total): print('Downloaded', current, 'out of', total, 'bytes: {:.2%}'.format(current / total)) await client.download_media(message, progress_callback=callback) """ # Downloading large documents may be slow enough to require a new file reference # to be obtained mid-download. Store (input chat, message id) so that the message # can be re-fetched. msg_data = None # TODO This won't work for messageService if isinstance(message, types.Message): date = message.date media = message.media msg_data = (message.input_chat, message.id) if message.input_chat else None else: date = datetime.datetime.now() media = message if isinstance(media, str): media = utils.resolve_bot_file_id(media) if isinstance(media, types.MessageService): if isinstance(message.action, types.MessageActionChatEditPhoto): media = media.photo if isinstance(media, types.MessageMediaWebPage): if isinstance(media.webpage, types.WebPage): media = media.webpage.document or media.webpage.photo if isinstance(media, (types.MessageMediaPhoto, types.Photo)): return await self._download_photo( media, file, date, thumb, progress_callback ) elif isinstance(media, (types.MessageMediaDocument, types.Document)): return await self._download_document( media, file, date, thumb, progress_callback, msg_data ) elif isinstance(media, types.MessageMediaContact) and thumb is None: return self._download_contact( media, file ) elif isinstance(media, (types.WebDocument, types.WebDocumentNoProxy)) and thumb is None: return await self._download_web_document( media, file, progress_callback ) async def download_file( self: 'TelegramClient', input_location: 'hints.FileLike', file: 'hints.OutFileLike' = None, *, part_size_kb: float = None, file_size: int = None, progress_callback: 'hints.ProgressCallback' = None, dc_id: int = None, key: bytes = None, iv: bytes = None) -> typing.Optional[bytes]: """ Low-level method to download files from their input location. .. note:: Generally, you should instead use `download_media`. This method is intended to be a bit more low-level. Arguments input_location (:tl:`InputFileLocation`): The file location from which the file will be downloaded. See `telethon.utils.get_input_location` source for a complete list of supported types. file (`str` | `file`, optional): The output file path, directory, or stream-like object. If the path exists and is a file, it will be overwritten. If the file path is `None` or `bytes`, then the result will be saved in memory and returned as `bytes`. part_size_kb (`int`, optional): Chunk size when downloading files. The larger, the less requests will be made (up to 512KB maximum). file_size (`int`, optional): The file size that is about to be downloaded, if known. Only used if ``progress_callback`` is specified. progress_callback (`callable`, optional): A callback function accepting two parameters: ``(downloaded bytes, total)``. Note that the ``total`` is the provided ``file_size``. dc_id (`int`, optional): The data center the library should connect to in order to download the file. You shouldn't worry about this. key ('bytes', optional): In case of an encrypted upload (secret chats) a key is supplied iv ('bytes', optional): In case of an encrypted upload (secret chats) an iv is supplied Example .. code-block:: python # Download a file and print its header data = await client.download_file(input_file, bytes) print(data[:16]) """ return await self._download_file( input_location, file, part_size_kb=part_size_kb, file_size=file_size, progress_callback=progress_callback, dc_id=dc_id, key=key, iv=iv, ) async def _download_file( self: 'TelegramClient', input_location: 'hints.FileLike', file: 'hints.OutFileLike' = None, *, part_size_kb: float = None, file_size: int = None, progress_callback: 'hints.ProgressCallback' = None, dc_id: int = None, key: bytes = None, iv: bytes = None, msg_data: tuple = None) -> typing.Optional[bytes]: if not part_size_kb: if not file_size: part_size_kb = 64 # Reasonable default else: part_size_kb = utils.get_appropriated_part_size(file_size) part_size = int(part_size_kb * 1024) if part_size % MIN_CHUNK_SIZE != 0: raise ValueError( 'The part size must be evenly divisible by 4096.') if isinstance(file, pathlib.Path): file = str(file.absolute()) in_memory = file is None or file is bytes if in_memory: f = io.BytesIO() elif isinstance(file, str): # Ensure that we'll be able to download the media helpers.ensure_parent_dir_exists(file) f = open(file, 'wb') else: f = file try: async for chunk in self._iter_download( input_location, request_size=part_size, dc_id=dc_id, msg_data=msg_data): if iv and key: chunk = AES.decrypt_ige(chunk, key, iv) r = f.write(chunk) if inspect.isawaitable(r): await r if progress_callback: r = progress_callback(f.tell(), file_size) if inspect.isawaitable(r): await r # Not all IO objects have flush (see #1227) if callable(getattr(f, 'flush', None)): f.flush() if in_memory: return f.getvalue() finally: if isinstance(file, str) or in_memory: f.close() def iter_download( self: 'TelegramClient', file: 'hints.FileLike', *, offset: int = 0, stride: int = None, limit: int = None, chunk_size: int = None, request_size: int = MAX_CHUNK_SIZE, file_size: int = None, dc_id: int = None ): """ Iterates over a file download, yielding chunks of the file. This method can be used to stream files in a more convenient way, since it offers more control (pausing, resuming, etc.) .. note:: Using a value for `offset` or `stride` which is not a multiple of the minimum allowed `request_size`, or if `chunk_size` is different from `request_size`, the library will need to do a bit more work to fetch the data in the way you intend it to. You normally shouldn't worry about this. Arguments file (`hints.FileLike`): The file of which contents you want to iterate over. offset (`int`, optional): The offset in bytes into the file from where the download should start. For example, if a file is 1024KB long and you just want the last 512KB, you would use ``offset=512 * 1024``. stride (`int`, optional): The stride of each chunk (how much the offset should advance between reading each chunk). This parameter should only be used for more advanced use cases. It must be bigger than or equal to the `chunk_size`. limit (`int`, optional): The limit for how many *chunks* will be yielded at most. chunk_size (`int`, optional): The maximum size of the chunks that will be yielded. Note that the last chunk may be less than this value. By default, it equals to `request_size`. request_size (`int`, optional): How many bytes will be requested to Telegram when more data is required. By default, as many bytes as possible are requested. If you would like to request data in smaller sizes, adjust this parameter. Note that values outside the valid range will be clamped, and the final value will also be a multiple of the minimum allowed size. file_size (`int`, optional): If the file size is known beforehand, you should set this parameter to said value. Depending on the type of the input file passed, this may be set automatically. dc_id (`int`, optional): The data center the library should connect to in order to download the file. You shouldn't worry about this. Yields `bytes` objects representing the chunks of the file if the right conditions are met, or `memoryview` objects instead. Example .. code-block:: python # Streaming `media` to an output file # After the iteration ends, the sender is cleaned up with open('photo.jpg', 'wb') as fd: async for chunk in client.iter_download(media): fd.write(chunk) # Fetching only the header of a file (32 bytes) # You should manually close the iterator in this case. # # "stream" is a common name for asynchronous generators, # and iter_download will yield `bytes` (chunks of the file). stream = client.iter_download(media, request_size=32) header = await stream.__anext__() # "manual" version of `async for` await stream.close() assert len(header) == 32 """ return self._iter_download( file, offset=offset, stride=stride, limit=limit, chunk_size=chunk_size, request_size=request_size, file_size=file_size, dc_id=dc_id, ) def _iter_download( self: 'TelegramClient', file: 'hints.FileLike', *, offset: int = 0, stride: int = None, limit: int = None, chunk_size: int = None, request_size: int = MAX_CHUNK_SIZE, file_size: int = None, dc_id: int = None, msg_data: tuple = None ): info = utils._get_file_info(file) if info.dc_id is not None: dc_id = info.dc_id if file_size is None: file_size = info.size file = info.location if chunk_size is None: chunk_size = request_size if limit is None and file_size is not None: limit = (file_size + chunk_size - 1) // chunk_size if stride is None: stride = chunk_size elif stride < chunk_size: raise ValueError('stride must be >= chunk_size') request_size -= request_size % MIN_CHUNK_SIZE if request_size < MIN_CHUNK_SIZE: request_size = MIN_CHUNK_SIZE elif request_size > MAX_CHUNK_SIZE: request_size = MAX_CHUNK_SIZE if chunk_size == request_size \ and offset % MIN_CHUNK_SIZE == 0 \ and stride % MIN_CHUNK_SIZE == 0 \ and (limit is None or offset % limit == 0): cls = _DirectDownloadIter self._log[__name__].info('Starting direct file download in chunks of ' '%d at %d, stride %d', request_size, offset, stride) else: cls = _GenericDownloadIter self._log[__name__].info('Starting indirect file download in chunks of ' '%d at %d, stride %d', request_size, offset, stride) return cls( self, limit, file=file, dc_id=dc_id, offset=offset, stride=stride, chunk_size=chunk_size, request_size=request_size, file_size=file_size, msg_data=msg_data, ) def _get_thumb(thumbs, thumb): # Seems Telegram has changed the order and put `PhotoStrippedSize` # last while this is the smallest (layer 116). Ensure we have the # sizes sorted correctly with a custom function. def sort_thumbs(thumb): if isinstance(thumb, types.PhotoStrippedSize): return 1, len(thumb.bytes) if isinstance(thumb, types.PhotoCachedSize): return 1, len(thumb.bytes) if isinstance(thumb, types.PhotoSize): return 1, thumb.size if isinstance(thumb, types.PhotoSizeProgressive): return 1, max(thumb.sizes) if isinstance(thumb, types.VideoSize): return 2, thumb.size # Empty size or invalid should go last return 0, 0 thumbs = list(sorted(thumbs, key=sort_thumbs)) for i in reversed(range(len(thumbs))): # :tl:`PhotoPathSize` is used for animated stickers preview, and the thumb is actually # a SVG path of the outline. Users expect thumbnails to be JPEG files, so pretend this # thumb size doesn't actually exist (#1655). if isinstance(thumbs[i], types.PhotoPathSize): thumbs.pop(i) if thumb is None: return thumbs[-1] elif isinstance(thumb, int): return thumbs[thumb] elif isinstance(thumb, str): return next((t for t in thumbs if t.type == thumb), None) elif isinstance(thumb, (types.PhotoSize, types.PhotoCachedSize, types.PhotoStrippedSize, types.VideoSize)): return thumb else: return None def _download_cached_photo_size(self: 'TelegramClient', size, file): # No need to download anything, simply write the bytes if isinstance(size, types.PhotoStrippedSize): data = utils.stripped_photo_to_jpg(size.bytes) else: data = size.bytes if file is bytes: return data elif isinstance(file, str): helpers.ensure_parent_dir_exists(file) f = open(file, 'wb') else: f = file try: f.write(data) finally: if isinstance(file, str): f.close() return file async def _download_photo(self: 'TelegramClient', photo, file, date, thumb, progress_callback): """Specialized version of .download_media() for photos""" # Determine the photo and its largest size if isinstance(photo, types.MessageMediaPhoto): photo = photo.photo if not isinstance(photo, types.Photo): return # Include video sizes here (but they may be None so provide an empty list) size = self._get_thumb(photo.sizes + (photo.video_sizes or []), thumb) if not size or isinstance(size, types.PhotoSizeEmpty): return if isinstance(size, types.VideoSize): file = self._get_proper_filename(file, 'video', '.mp4', date=date) else: file = self._get_proper_filename(file, 'photo', '.jpg', date=date) if isinstance(size, (types.PhotoCachedSize, types.PhotoStrippedSize)): return self._download_cached_photo_size(size, file) if isinstance(size, types.PhotoSizeProgressive): file_size = max(size.sizes) else: file_size = size.size result = await self.download_file( types.InputPhotoFileLocation( id=photo.id, access_hash=photo.access_hash, file_reference=photo.file_reference, thumb_size=size.type ), file, file_size=file_size, progress_callback=progress_callback ) return result if file is bytes else file def _get_kind_and_names(attributes): """Gets kind and possible names for :tl:`DocumentAttribute`.""" kind = 'document' possible_names = [] for attr in attributes: if isinstance(attr, types.DocumentAttributeFilename): possible_names.insert(0, attr.file_name) elif isinstance(attr, types.DocumentAttributeAudio): kind = 'audio' if attr.performer and attr.title: possible_names.append('{} - {}'.format( attr.performer, attr.title )) elif attr.performer: possible_names.append(attr.performer) elif attr.title: possible_names.append(attr.title) elif attr.voice: kind = 'voice' return kind, possible_names async def _download_document( self, document, file, date, thumb, progress_callback, msg_data): """Specialized version of .download_media() for documents.""" if isinstance(document, types.MessageMediaDocument): document = document.document if not isinstance(document, types.Document): return if thumb is None: kind, possible_names = self._get_kind_and_names(document.attributes) file = self._get_proper_filename( file, kind, utils.get_extension(document), date=date, possible_names=possible_names ) size = None else: file = self._get_proper_filename(file, 'photo', '.jpg', date=date) size = self._get_thumb(document.thumbs, thumb) if isinstance(size, (types.PhotoCachedSize, types.PhotoStrippedSize)): return self._download_cached_photo_size(size, file) result = await self._download_file( types.InputDocumentFileLocation( id=document.id, access_hash=document.access_hash, file_reference=document.file_reference, thumb_size=size.type if size else '' ), file, file_size=size.size if size else document.size, progress_callback=progress_callback, msg_data=msg_data, ) return result if file is bytes else file def _download_contact(cls, mm_contact, file): """ Specialized version of .download_media() for contacts. Will make use of the vCard 4.0 format. """ first_name = mm_contact.first_name last_name = mm_contact.last_name phone_number = mm_contact.phone_number # Remove these pesky characters first_name = first_name.replace(';', '') last_name = (last_name or '').replace(';', '') result = ( 'BEGIN:VCARD\n' 'VERSION:4.0\n' 'N:{f};{l};;;\n' 'FN:{f} {l}\n' 'TEL;TYPE=cell;VALUE=uri:tel:+{p}\n' 'END:VCARD\n' ).format(f=first_name, l=last_name, p=phone_number).encode('utf-8') if file is bytes: return result elif isinstance(file, str): file = cls._get_proper_filename( file, 'contact', '.vcard', possible_names=[first_name, phone_number, last_name] ) f = open(file, 'wb') else: f = file try: f.write(result) finally: # Only close the stream if we opened it if isinstance(file, str): f.close() return file async def _download_web_document(cls, web, file, progress_callback): """ Specialized version of .download_media() for web documents. """ if not aiohttp: raise ValueError( 'Cannot download web documents without the aiohttp ' 'dependency install it (pip install aiohttp)' ) # TODO Better way to get opened handles of files and auto-close in_memory = file is bytes if in_memory: f = io.BytesIO() elif isinstance(file, str): kind, possible_names = cls._get_kind_and_names(web.attributes) file = cls._get_proper_filename( file, kind, utils.get_extension(web), possible_names=possible_names ) f = open(file, 'wb') else: f = file try: with aiohttp.ClientSession() as session: # TODO Use progress_callback; get content length from response # https://github.com/telegramdesktop/tdesktop/blob/c7e773dd9aeba94e2be48c032edc9a78bb50234e/Telegram/SourceFiles/ui/images.cpp#L1318-L1319 async with session.get(web.url) as response: while True: chunk = await response.content.read(128 * 1024) if not chunk: break f.write(chunk) finally: if isinstance(file, str) or file is bytes: f.close() return f.getvalue() if in_memory else file def _get_proper_filename(file, kind, extension, date=None, possible_names=None): """Gets a proper filename for 'file', if this is a path. 'kind' should be the kind of the output file (photo, document...) 'extension' should be the extension to be added to the file if the filename doesn't have any yet 'date' should be when this file was originally sent, if known 'possible_names' should be an ordered list of possible names If no modification is made to the path, any existing file will be overwritten. If any modification is made to the path, this method will ensure that no existing file will be overwritten. """ if isinstance(file, pathlib.Path): file = str(file.absolute()) if file is not None and not isinstance(file, str): # Probably a stream-like object, we cannot set a filename here return file if file is None: file = '' elif os.path.isfile(file): # Make no modifications to valid existing paths return file if os.path.isdir(file) or not file: try: name = None if possible_names is None else next( x for x in possible_names if x ) except StopIteration: name = None if not name: if not date: date = datetime.datetime.now() name = '{}_{}-{:02}-{:02}_{:02}-{:02}-{:02}'.format( kind, date.year, date.month, date.day, date.hour, date.minute, date.second, ) file = os.path.join(file, name) directory, name = os.path.split(file) name, ext = os.path.splitext(name) if not ext: ext = extension result = os.path.join(directory, name + ext) if not os.path.isfile(result): return result i = 1 while True: result = os.path.join(directory, '{} ({}){}'.format(name, i, ext)) if not os.path.isfile(result): return result i += 1