FileFormatter

class lsst.daf.butler.formatters.fileFormatter.FileFormatter

Bases: lsst.daf.butler.Formatter

Interface for reading and writing files on a POSIX file system.

Attributes Summary

extension

Default file extension to use for writing files.

Methods Summary

predictPath(location)	Return the path that would be returned by write, without actually writing.
read(fileDescriptor[, component])	Read data from a file.
write(inMemoryDataset, fileDescriptor)	Write a Python object to a file.

Attributes Documentation

extension = None

Default file extension to use for writing files. None means that no modifications will be made to the supplied file extension.

Methods Documentation

predictPath(location)

Return the path that would be returned by write, without actually writing.

location : Location

The location to simulate writing to.

read(fileDescriptor, component=None)

Read data from a file.

Parameters:

fileDescriptor : FileDescriptor

Identifies the file to read, type to read it into and parameters to be used for reading.

component : str, optional

Component to read from the file. Only used if the StorageClass for reading differed from the StorageClass used to write the file.

Returns:

inMemoryDataset : object

The requested data as a Python object. The type of object is controlled by the specific formatter.

Raises:

ValueError

Component requested but this file does not seem to be a concrete composite.

write(inMemoryDataset, fileDescriptor)

Write a Python object to a file.

Parameters:

inMemoryDataset : object

The Python object to store.

fileDescriptor : FileDescriptor

Identifies the file to read, type to read it into and parameters to be used for reading.

Returns:

path : str

The URI where the primary file is stored.