gridfs
– Tools for working with GridFS¶
GridFS is a specification for storing large objects in Mongo.
The gridfs
package is an implementation of GridFS on top of
pymongo
, exposing a file-like interface.
-
class
gridfs.
GridFS
(database, collection=’fs’)¶ Create a new instance of
GridFS
.Raises
TypeError
if database is not an instance ofDatabase
.Parameters: - database: database to use
- collection (optional): root collection to use
Changed in version 3.1: Indexes are only ensured on the first write to the DB.
Changed in version 3.0: database must use an acknowledged
write_concern
-
delete
(file_id, session=None)¶ Delete a file from GridFS by
"_id"
.Deletes all data belonging to the file with
"_id"
: file_id.Warning
Any processes/threads reading from the file while this method is executing will likely see an invalid/corrupt file. Care should be taken to avoid concurrent reads to a file while it is being deleted.
Note
Deletes of non-existent files are considered successful since the end result is the same: no file with that _id remains.
Parameters: - file_id:
"_id"
of the file to delete - session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.Changed in version 3.1:
delete
no longer ensures indexes.- file_id:
-
exists
(document_or_id=None, session=None, **kwargs)¶ Check if a file exists in this instance of
GridFS
.The file to check for can be specified by the value of its
_id
key, or by passing in a query document. A query document can be passed in as dictionary, or by using keyword arguments. Thus, the following three calls are equivalent:>>> fs.exists(file_id) >>> fs.exists({"_id": file_id}) >>> fs.exists(_id=file_id)
As are the following two calls:
>>> fs.exists({"filename": "mike.txt"}) >>> fs.exists(filename="mike.txt")
And the following two:
>>> fs.exists({"foo": {"$gt": 12}}) >>> fs.exists(foo={"$gt": 12})
Returns
True
if a matching file exists,False
otherwise. Calls toexists()
will not automatically create appropriate indexes; application developers should be sure to create indexes if needed and as appropriate.Parameters: - document_or_id (optional): query document, or _id of the document to check for
- session (optional): a
ClientSession
- **kwargs (optional): keyword arguments are used as a query document, if they’re present.
Changed in version 3.6: Added
session
parameter.
-
find
(*args, **kwargs)¶ Query GridFS for files.
Returns a cursor that iterates across files matching arbitrary queries on the files collection. Can be combined with other modifiers for additional control. For example:
for grid_out in fs.find({"filename": "lisa.txt"}, no_cursor_timeout=True): data = grid_out.read()
would iterate through all versions of “lisa.txt” stored in GridFS. Note that setting no_cursor_timeout to True may be important to prevent the cursor from timing out during long multi-file processing work.
As another example, the call:
most_recent_three = fs.find().sort("uploadDate", -1).limit(3)
would return a cursor to the three most recently uploaded files in GridFS.
Follows a similar interface to
find()
inCollection
.If a
ClientSession
is passed tofind()
, all returnedGridOut
instances are associated with that session.Parameters: - filter (optional): a SON object specifying elements which must be present for a document to be included in the result set
- skip (optional): the number of files to omit (from the start of the result set) when returning the results
- limit (optional): the maximum number of results to return
- no_cursor_timeout (optional): if False (the default), any returned cursor is closed by the server after 10 minutes of inactivity. If set to True, the returned cursor will never time out on the server. Care should be taken to ensure that cursors with no_cursor_timeout turned on are properly closed.
- sort (optional): a list of (key, direction) pairs
specifying the sort order for this query. See
sort()
for details.
Raises
TypeError
if any of the arguments are of improper type. Returns an instance ofGridOutCursor
corresponding to this query.Changed in version 3.0: Removed the read_preference, tag_sets, and secondary_acceptable_latency_ms options.
New in version 2.7.
-
find_one
(filter=None, session=None, *args, **kwargs)¶ Get a single file from gridfs.
All arguments to
find()
are also valid arguments forfind_one()
, although any limit argument will be ignored. Returns a singleGridOut
, orNone
if no matching file is found. For example:file = fs.find_one({"filename": "lisa.txt"})
Parameters: - filter (optional): a dictionary specifying
the query to be performing OR any other type to be used as
the value for a query for
"_id"
in the file collection. - *args (optional): any additional positional arguments are
the same as the arguments to
find()
. - session (optional): a
ClientSession
- **kwargs (optional): any additional keyword arguments
are the same as the arguments to
find()
.
Changed in version 3.6: Added
session
parameter.- filter (optional): a dictionary specifying
the query to be performing OR any other type to be used as
the value for a query for
-
get
(file_id, session=None)¶ Get a file from GridFS by
"_id"
.Returns an instance of
GridOut
, which provides a file-like interface for reading.Parameters: - file_id:
"_id"
of the file to get - session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.- file_id:
-
get_last_version
(filename=None, session=None, **kwargs)¶ Get the most recent version of a file in GridFS by
"filename"
or metadata fields.Equivalent to calling
get_version()
with the default version (-1
).Parameters: - filename:
"filename"
of the file to get, or None - session (optional): a
ClientSession
- **kwargs (optional): find files by custom metadata.
Changed in version 3.6: Added
session
parameter.- filename:
-
get_version
(filename=None, version=-1, session=None, **kwargs)¶ Get a file from GridFS by
"filename"
or metadata fields.Returns a version of the file in GridFS whose filename matches filename and whose metadata fields match the supplied keyword arguments, as an instance of
GridOut
.Version numbering is a convenience atop the GridFS API provided by MongoDB. If more than one file matches the query (either by filename alone, by metadata fields, or by a combination of both), then version
-1
will be the most recently uploaded matching file,-2
the second most recently uploaded, etc. Version0
will be the first version uploaded,1
the second version, etc. So if three versions have been uploaded, then version0
is the same as version-3
, version1
is the same as version-2
, and version2
is the same as version-1
.Raises
NoFile
if no such version of that file exists.Parameters: - filename:
"filename"
of the file to get, or None - version (optional): version of the file to get (defaults to -1, the most recent version uploaded)
- session (optional): a
ClientSession
- **kwargs (optional): find files by custom metadata.
Changed in version 3.6: Added
session
parameter.Changed in version 3.1:
get_version
no longer ensures indexes.- filename:
-
list
(session=None)¶ List the names of all files stored in this instance of
GridFS
.Parameters: - session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.Changed in version 3.1:
list
no longer ensures indexes.- session (optional): a
-
new_file
(**kwargs)¶ Create a new file in GridFS.
Returns a new
GridIn
instance to which data can be written. Any keyword arguments will be passed through toGridIn()
.If the
"_id"
of the file is manually specified, it must not already exist in GridFS. OtherwiseFileExists
is raised.Parameters: - **kwargs (optional): keyword arguments for file creation
-
put
(data, **kwargs)¶ Put data in GridFS as a new file.
Equivalent to doing:
try: f = new_file(**kwargs) f.write(data) finally: f.close()
data can be either an instance of
str
(bytes
in python 3) or a file-like object providing aread()
method. If an encoding keyword argument is passed, data can also be aunicode
(str
in python 3) instance, which will be encoded as encoding before being written. Any keyword arguments will be passed through to the created file - seeGridIn()
for possible arguments. Returns the"_id"
of the created file.If the
"_id"
of the file is manually specified, it must not already exist in GridFS. OtherwiseFileExists
is raised.Parameters: - data: data to be written as a file.
- **kwargs (optional): keyword arguments for file creation
Changed in version 3.0: w=0 writes to GridFS are now prohibited.
-
class
gridfs.
GridFSBucket
(db, bucket_name=’fs’, chunk_size_bytes=261120, write_concern=None, read_preference=None)¶ Create a new instance of
GridFSBucket
.Raises
TypeError
if database is not an instance ofDatabase
.Raises
ConfigurationError
if write_concern is not acknowledged.Parameters: - database: database to use.
- bucket_name (optional): The name of the bucket. Defaults to ‘fs’.
- chunk_size_bytes (optional): The chunk size in bytes. Defaults to 255KB.
- write_concern (optional): The
WriteConcern
to use. IfNone
(the default) db.write_concern is used. - read_preference (optional): The read preference to use. If
None
(the default) db.read_preference is used.
New in version 3.1.
-
delete
(file_id, session=None)¶ Given an file_id, delete this stored file’s files collection document and associated chunks from a GridFS bucket.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) # Get _id of file to delete file_id = fs.upload_from_stream("test_file", "data I want to store!") fs.delete(file_id)
Raises
NoFile
if no file with file_id exists.Parameters: - file_id: The _id of the file to be deleted.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
download_to_stream
(file_id, destination, session=None)¶ Downloads the contents of the stored file specified by file_id and writes the contents to destination.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) # Get _id of file to read file_id = fs.upload_from_stream("test_file", "data I want to store!") # Get file to write to file = open('myfile','wb+') fs.download_to_stream(file_id, file) file.seek(0) contents = file.read()
Raises
NoFile
if no file with file_id exists.Parameters: - file_id: The _id of the file to be downloaded.
- destination: a file-like object implementing
write()
. - session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
download_to_stream_by_name
(filename, destination, revision=-1, session=None)¶ Write the contents of filename (with optional revision) to destination.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) # Get file to write to file = open('myfile','wb') fs.download_to_stream_by_name("test_file", file)
Raises
NoFile
if no such version of that file exists.Raises
ValueError
if filename is not a string.Parameters: - filename: The name of the file to read from.
- destination: A file-like object that implements
write()
. - revision (optional): Which revision (documents with the same filename and different uploadDate) of the file to retrieve. Defaults to -1 (the most recent revision).
- session (optional): a
ClientSession
Note: Revision numbers are defined as follows:
- 0 = the original stored file
- 1 = the first revision
- 2 = the second revision
- etc…
- -2 = the second most recent revision
- -1 = the most recent revision
Changed in version 3.6: Added
session
parameter.
-
find
(*args, **kwargs)¶ Find and return the files collection documents that match
filter
Returns a cursor that iterates across files matching arbitrary queries on the files collection. Can be combined with other modifiers for additional control.
For example:
for grid_data in fs.find({"filename": "lisa.txt"}, no_cursor_timeout=True): data = grid_data.read()
would iterate through all versions of “lisa.txt” stored in GridFS. Note that setting no_cursor_timeout to True may be important to prevent the cursor from timing out during long multi-file processing work.
As another example, the call:
most_recent_three = fs.find().sort("uploadDate", -1).limit(3)
would return a cursor to the three most recently uploaded files in GridFS.
Follows a similar interface to
find()
inCollection
.If a
ClientSession
is passed tofind()
, all returnedGridOut
instances are associated with that session.Parameters: - filter: Search query.
- batch_size (optional): The number of documents to return per batch.
- limit (optional): The maximum number of documents to return.
- no_cursor_timeout (optional): The server normally times out idle cursors after an inactivity period (10 minutes) to prevent excess memory use. Set this option to True prevent that.
- skip (optional): The number of documents to skip before returning.
- sort (optional): The order by which to sort results. Defaults to None.
-
open_download_stream
(file_id, session=None)¶ Opens a Stream from which the application can read the contents of the stored file specified by file_id.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) # get _id of file to read. file_id = fs.upload_from_stream("test_file", "data I want to store!") grid_out = fs.open_download_stream(file_id) contents = grid_out.read()
Returns an instance of
GridOut
.Raises
NoFile
if no file with file_id exists.Parameters: - file_id: The _id of the file to be downloaded.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
open_download_stream_by_name
(filename, revision=-1, session=None)¶ Opens a Stream from which the application can read the contents of filename and optional revision.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) grid_out = fs.open_download_stream_by_name("test_file") contents = grid_out.read()
Returns an instance of
GridOut
.Raises
NoFile
if no such version of that file exists.Raises
ValueError
filename is not a string.Parameters: - filename: The name of the file to read from.
- revision (optional): Which revision (documents with the same filename and different uploadDate) of the file to retrieve. Defaults to -1 (the most recent revision).
- session (optional): a
ClientSession
Note: Revision numbers are defined as follows:
- 0 = the original stored file
- 1 = the first revision
- 2 = the second revision
- etc…
- -2 = the second most recent revision
- -1 = the most recent revision
Changed in version 3.6: Added
session
parameter.
-
open_upload_stream
(filename, chunk_size_bytes=None, metadata=None, session=None)¶ Opens a Stream that the application can write the contents of the file to.
The user must specify the filename, and can choose to add any additional information in the metadata field of the file document or modify the chunk size. For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) grid_in, file_id = fs.open_upload_stream( "test_file", chunk_size_bytes=4, metadata={"contentType": "text/plain"}) grid_in.write("data I want to store!") grid_in.close() # uploaded on close
Returns an instance of
GridIn
.Raises
NoFile
if no such version of that file exists. RaisesValueError
if filename is not a string.Parameters: - filename: The name of the file to upload.
- chunk_size_bytes (options): The number of bytes per chunk of this
file. Defaults to the chunk_size_bytes in
GridFSBucket
. - metadata (optional): User data for the ‘metadata’ field of the files collection document. If not provided the metadata field will be omitted from the files collection document.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
open_upload_stream_with_id
(file_id, filename, chunk_size_bytes=None, metadata=None, session=None)¶ Opens a Stream that the application can write the contents of the file to.
The user must specify the file id and filename, and can choose to add any additional information in the metadata field of the file document or modify the chunk size. For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) grid_in, file_id = fs.open_upload_stream( ObjectId(), "test_file", chunk_size_bytes=4, metadata={"contentType": "text/plain"}) grid_in.write("data I want to store!") grid_in.close() # uploaded on close
Returns an instance of
GridIn
.Raises
NoFile
if no such version of that file exists. RaisesValueError
if filename is not a string.Parameters: - file_id: The id to use for this file. The id must not have already been used for another file.
- filename: The name of the file to upload.
- chunk_size_bytes (options): The number of bytes per chunk of this
file. Defaults to the chunk_size_bytes in
GridFSBucket
. - metadata (optional): User data for the ‘metadata’ field of the files collection document. If not provided the metadata field will be omitted from the files collection document.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
rename
(file_id, new_filename, session=None)¶ Renames the stored file with the specified file_id.
For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) # Get _id of file to rename file_id = fs.upload_from_stream("test_file", "data I want to store!") fs.rename(file_id, "new_test_name")
Raises
NoFile
if no file with file_id exists.Parameters: - file_id: The _id of the file to be renamed.
- new_filename: The new name of the file.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
upload_from_stream
(filename, source, chunk_size_bytes=None, metadata=None, session=None)¶ Uploads a user file to a GridFS bucket.
Reads the contents of the user file from source and uploads it to the file filename. Source can be a string or file-like object. For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) file_id = fs.upload_from_stream( "test_file", "data I want to store!", chunk_size_bytes=4, metadata={"contentType": "text/plain"})
Returns the _id of the uploaded file.
Raises
NoFile
if no such version of that file exists. RaisesValueError
if filename is not a string.Parameters: - filename: The name of the file to upload.
- source: The source stream of the content to be uploaded. Must be
a file-like object that implements
read()
or a string. - chunk_size_bytes (options): The number of bytes per chunk of this
file. Defaults to the chunk_size_bytes of
GridFSBucket
. - metadata (optional): User data for the ‘metadata’ field of the files collection document. If not provided the metadata field will be omitted from the files collection document.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
-
upload_from_stream_with_id
(file_id, filename, source, chunk_size_bytes=None, metadata=None, session=None)¶ Uploads a user file to a GridFS bucket with a custom file id.
Reads the contents of the user file from source and uploads it to the file filename. Source can be a string or file-like object. For example:
my_db = MongoClient().test fs = GridFSBucket(my_db) file_id = fs.upload_from_stream( ObjectId(), "test_file", "data I want to store!", chunk_size_bytes=4, metadata={"contentType": "text/plain"})
Raises
NoFile
if no such version of that file exists. RaisesValueError
if filename is not a string.Parameters: - file_id: The id to use for this file. The id must not have already been used for another file.
- filename: The name of the file to upload.
- source: The source stream of the content to be uploaded. Must be
a file-like object that implements
read()
or a string. - chunk_size_bytes (options): The number of bytes per chunk of this
file. Defaults to the chunk_size_bytes of
GridFSBucket
. - metadata (optional): User data for the ‘metadata’ field of the files collection document. If not provided the metadata field will be omitted from the files collection document.
- session (optional): a
ClientSession
Changed in version 3.6: Added
session
parameter.
Sub-modules: