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bonobo/bonobo/nodes/io/base.py
Romain Dorgueil 7f34737c3a wip documentation
2017-11-07 11:52:26 +01:00

95 lines
3.0 KiB
Python

from bonobo import settings
from bonobo.config import Configurable, ContextProcessor, Option, Service
from bonobo.errors import UnrecoverableValueError, UnrecoverableNotImplementedError
from bonobo.structs.bags import Bag
class IOFormatEnabled(Configurable):
ioformat = Option(default=settings.IOFORMAT.get, __doc__='''
Input/output format for rows. This will be removed in 0.6, so please use the kwargs format.
''')
def get_input(self, *args, **kwargs):
if self.ioformat == settings.IOFORMAT_ARG0:
if len(args) != 1 or len(kwargs):
raise UnrecoverableValueError(
'Wrong input formating: IOFORMAT=ARG0 implies one arg and no kwargs, got args={!r} and kwargs={!r}.'.
format(args, kwargs)
)
return args[0]
if self.ioformat == settings.IOFORMAT_KWARGS:
if len(args) or not len(kwargs):
raise UnrecoverableValueError(
'Wrong input formating: IOFORMAT=KWARGS ioformat implies no arg, got args={!r} and kwargs={!r}.'.
format(args, kwargs)
)
return kwargs
raise UnrecoverableNotImplementedError('Unsupported format.')
def get_output(self, row):
if self.ioformat == settings.IOFORMAT_ARG0:
return row
if self.ioformat == settings.IOFORMAT_KWARGS:
return Bag(**row)
raise UnrecoverableNotImplementedError('Unsupported format.')
class FileHandler(Configurable):
"""Abstract component factory for file-related components.
Args:
eol (str): which
mode (str): which mode to use when opening the file.
fs (str): service name to use for filesystem.
"""
path = Option(str, required=True, positional=True, __doc__='''
Path to use within the provided filesystem.
''') # type: str
eol = Option(str, default='\n', __doc__='''
Character to use as line separator.
''') # type: str
mode = Option(str, __doc__='''
What mode to use for open() call.
''') # type: str
encoding = Option(str, default='utf-8', __doc__='''
Encoding.
''') # type: str
fs = Service('fs', __doc__='''
The filesystem instance to use.
''') # type: str
@ContextProcessor
def file(self, context, fs):
with self.open(fs) as file:
yield file
def open(self, fs):
return fs.open(self.path, self.mode, encoding=self.encoding)
class Reader:
"""Abstract component factory for readers.
"""
def __call__(self, *args, **kwargs):
yield from self.read(*args, **kwargs)
def read(self, *args, **kwargs):
raise NotImplementedError('Abstract.')
class Writer:
"""Abstract component factory for writers.
"""
def __call__(self, *args, **kwargs):
return self.write(*args, **kwargs)
def write(self, *args, **kwargs):
raise NotImplementedError('Abstract.')