grid_file
– Tools for representing files stored in GridFS¶
Tools for representing files stored in GridFS.
-
class
gridfs.grid_file.
GridIn
(root_collection, session=None, **kwargs)¶ Write a file to GridFS
Application developers should generally not need to instantiate this class directly - instead see the methods provided by
GridFS
.Raises
TypeError
if root_collection is not an instance ofCollection
.Any of the file level options specified in the GridFS Spec may be passed as keyword arguments. Any additional keyword arguments will be set as additional fields on the file document. Valid keyword arguments include:
"_id"
: unique ID for this file (default:ObjectId
) - this"_id"
must not have already been used for another file"filename"
: human name for the file"contentType"
or"content_type"
: valid mime-type for the file"chunkSize"
or"chunk_size"
: size of each of the chunks, in bytes (default: 255 kb)"encoding"
: encoding used for this file. In Python 2, anyunicode
that is written to the file will be converted to astr
. In Python 3, anystr
that is written to the file will be converted tobytes
.
Parameters: - root_collection: root collection to write to
- session (optional): a
ClientSession
to use for all commands - **kwargs (optional): file level options (see above)
Changed in version 3.6: Added
session
parameter.Changed in version 3.0: root_collection must use an acknowledged
write_concern
-
_id
¶ The
'_id'
value for this file.This attribute is read-only.
-
abort
()¶ Remove all chunks/files that may have been uploaded and close.
-
chunk_size
¶ Chunk size for this file.
This attribute is read-only.
-
close
()¶ Flush the file and close it.
A closed file cannot be written any more. Calling
close()
more than once is allowed.
-
closed
¶ Is this file closed?
-
content_type
¶ Mime-type for this file.
-
filename
¶ Name of this file.
-
length
¶ Length (in bytes) of this file.
This attribute is read-only and can only be read after
close()
has been called.
-
md5
¶ MD5 of the contents of this file (generated on the server).
This attribute is read-only and can only be read after
close()
has been called.
-
name
¶ Alias for filename.
-
upload_date
¶ Date that this file was uploaded.
This attribute is read-only and can only be read after
close()
has been called.
-
write
(data)¶ Write data to the file. There is no return value.
data can be either a string of bytes or a file-like object (implementing
read()
). If the file has anencoding
attribute, data can also be aunicode
(str
in python 3) instance, which will be encoded asencoding
before being written.Due to buffering, the data may not actually be written to the database until the
close()
method is called. RaisesValueError
if this file is already closed. RaisesTypeError
if data is not an instance ofstr
(bytes
in python 3), a file-like object, or an instance ofunicode
(str
in python 3). Unicode data is only allowed if the file has anencoding
attribute.Parameters: - data: string of bytes or file-like object to be written to the file
-
writelines
(sequence)¶ Write a sequence of strings to the file.
Does not add seperators.
-
class
gridfs.grid_file.
GridOut
(root_collection, file_id=None, file_document=None, session=None)¶ Read a file from GridFS
Application developers should generally not need to instantiate this class directly - instead see the methods provided by
GridFS
.Either file_id or file_document must be specified, file_document will be given priority if present. Raises
TypeError
if root_collection is not an instance ofCollection
.Parameters: - root_collection: root collection to read from
- file_id (optional): value of
"_id"
for the file to read - file_document (optional): file document from root_collection.files
- session (optional): a
ClientSession
to use for all commands
Changed in version 3.6: Added
session
parameter.Changed in version 3.0: Creating a GridOut does not immediately retrieve the file metadata from the server. Metadata is fetched when first needed.
-
_id
¶ The
'_id'
value for this file.This attribute is read-only.
-
__iter__
()¶ Return an iterator over all of this file’s data.
The iterator will return chunk-sized instances of
str
(bytes
in python 3). This can be useful when serving files using a webserver that handles such an iterator efficiently.
-
aliases
¶ List of aliases for this file.
This attribute is read-only.
-
chunk_size
¶ Chunk size for this file.
This attribute is read-only.
-
close
()¶ Make GridOut more generically file-like.
-
content_type
¶ Mime-type for this file.
This attribute is read-only.
-
filename
¶ Name of this file.
This attribute is read-only.
-
length
¶ Length (in bytes) of this file.
This attribute is read-only.
-
md5
¶ MD5 of the contents of this file (generated on the server).
This attribute is read-only.
-
metadata
¶ Metadata attached to this file.
This attribute is read-only.
-
name
¶ Alias for filename.
This attribute is read-only.
-
read
(size=-1)¶ Read at most size bytes from the file (less if there isn’t enough data).
The bytes are returned as an instance of
str
(bytes
in python 3). If size is negative or omitted all data is read.Parameters: - size (optional): the number of bytes to read
-
readchunk
()¶ Reads a chunk at a time. If the current position is within a chunk the remainder of the chunk is returned.
-
readline
(size=-1)¶ Read one line or up to size bytes from the file.
Parameters: - size (optional): the maximum number of bytes to read
-
seek
(pos, whence=0)¶ Set the current position of this file.
Parameters: - pos: the position (or offset if using relative positioning) to seek to
- whence (optional): where to seek
from.
os.SEEK_SET
(0
) for absolute file positioning,os.SEEK_CUR
(1
) to seek relative to the current position,os.SEEK_END
(2
) to seek relative to the file’s end.
-
tell
()¶ Return the current position of this file.
-
upload_date
¶ Date that this file was first uploaded.
This attribute is read-only.
-
class
gridfs.grid_file.
GridOutCursor
(collection, filter=None, skip=0, limit=0, no_cursor_timeout=False, sort=None, batch_size=0, session=None)¶ Create a new cursor, similar to the normal
Cursor
.Should not be called directly by application developers - see the
GridFS
methodfind()
instead.-
next
()¶ Get next GridOut object from cursor.
-