Layout Factories¶
Each layout has up to four string converters. There are readers and writers, each of which has a variant for individual strings (Line) or entire files (Dict).
-
txf.layouts.
LineReaderFactory
(name, layout, iterable, **config)¶ Constructs a
LineReader
for the givenlayout
. The reader will parse each string into a string tuple.- Parameters
name (str) – The name of the calling transform.
layout (str) – The string layout to read.
iterable – The source of the strings to parse.
config – Optional configuration parameters for the
LineReader
.
- Returns
An
iterable
that generates parsed tuples of values- Raises
TransformException – if the layout is unknown or the iterable is not
iterable
.
-
txf.layouts.
DictReaderFactory
(name, layout, iterable, fieldnames, **config)¶ Constructs a
DictReader
for the givenlayout
. The reader will parse each string into a record.- Parameters
name (str) – The name of the calling transform.
layout (str) – The string layout to read.
iterable – The source of the strings to parse.
fieldnames (fields) – The fields to read from the record.
config – Optional configuration parameters for the
DictReader
.
- Returns
An
iterable
that generates parsed records- Raises
TransformException – if the layout is unknown or the iterable is not
iterable
.
-
txf.layouts.
LineWriterFactory
(name, layout, outfile, fieldnames, **config)¶ Constructs a
DictWriter
for the givenlayout
that convertstuple
s into strings in the given layout and writes them to the output.- Parameters
name (str) – The name of the calling transform.
layout (str) – The string layout to write.
outfile – The destination for the strings.
fieldnames (fields) – The fields corresponding to the
tuple
values.config – Optional configuration parameters for the :py:class`DictReader`.
- Returns
LineWriter
that writes layouttuple
s- Raises
TransformException – if the layout is unknown or the outfile does not have a
write()
method
-
txf.layouts.
DictWriterFactory
(name, layout, outfile, fieldnames, **config)¶ Constructs a
DictWriter
for the givenlayout
that converts records into strings in the given layout and writes them to the output.- Parameters
name (str) – The name of the calling transform.
layout (str) – The string layout to write.
outfile (writable) – The destination for the strings.
fieldnames (fields) – The fields corresponding to the tuple values.
config – Optional configuration parameters for the
DictReader
.
- Returns
A
DictWriter
that writes layout tuples- Raises
TransformException – if the layout is unknown or the outfile does not have a
write()
method
-
txf.layouts.
GetLayout
(layout)¶ Returns the factories for a layout code. If there are no entries, the layout is not defined.
- Parameters
layout (str) – The layout
- Returns
The factories.
- Return type
dict
-
txf.layouts.
RegisterLayout
(layout, namespace)¶ Adds factories for a layout code, reading them from the
dir()
of the namespace. Existing factories are replaced.- Parameters
namespace – An object containing the factories.
-
txf.layouts.
UnregisterLayout
(layout)¶ Remove the factories for the layout.
- Parameters
namespace – An object containing the factories.