def evaluate(expression,
start=None,
end=None,
loader=None,
logger=None,
backend=None,
**kwargs):
'''Evaluate the timeseries ``expression`` into
an instance of an instance of :class:`dynts.dsl.dslresult` which can be used
to obtain timeseries and/or scatters.
This is probably the most used function of the library.
:parameter expression: A timeseries expression string or an instance
of :class:`dynts.dsl.Expr` obtained using
the :func:`dynts.parse` function.
:parameter start: Start date or ``None``.
:parameter end: End date or ``None``. If not provided today values is used.
:parameter loader: Optional :class:`dynts.data.TimeSerieLoader`
class or instance to use.
Default ``None``.
:parameter logger: Optional python logging instance, used if you required
logging.
Default ``None``.
:parameter backend: :class:`dynts.TimeSeries` backend name or ``None``.
The ``expression`` is parsed and the :class:`dynts.dsl.Symbol` are sent to the
:class:`dynts.data.TimeSerieLoader` instance for retrieving
actual timeseries data.
It returns an instance of :class:`dynts.dsl.dslresult`.
Typical usage::
>>> import dynts
>>> r = dynts.evaluate('min(GS,window=30)')
>>> r
min(GS,window=30)
>>> ts = r.ts()
'''
if isinstance(expression, strtype):
expression = parse(expression)
if not expression or expression.malformed():
raise CouldNotParse(expression)
symbols = expression.symbols()
start = start if not start else todate(start)
end = end if not end else todate(end)
data = providers.load(symbols,
start,
end,
loader=loader,
logger=logger,
backend=backend,
**kwargs)
return dslresult(expression, data, backend=backend)
def evaluate(expression, start = None, end = None,
loader = None, logger = None, backend = None,
**kwargs):
'''Evaluate the timeseries ``expression`` into
an instance of an instance of :class:`dynts.dsl.dslresult` which can be used
to obtain timeseries and/or scatters.
This is probably the most used function of the library.
:parameter expression: A timeseries expression string or an instance
of :class:`dynts.dsl.Expr` obtained using
the :func:`dynts.parse` function.
:parameter start: Start date or ``None``.
:parameter end: End date or ``None``. If not provided today values is used.
:parameter loader: Optional :class:`dynts.data.TimeSerieLoader`
class or instance to use.
Default ``None``.
:parameter logger: Optional python logging instance, used if you required
logging.
Default ``None``.
:parameter backend: :class:`dynts.TimeSeries` backend name or ``None``.
The ``expression`` is parsed and the :class:`dynts.dsl.Symbol` are sent to the
:class:`dynts.data.TimeSerieLoader` instance for retrieving
actual timeseries data.
It returns an instance of :class:`dynts.dsl.dslresult`.
Typical usage::
>>> import dynts
>>> r = dynts.evaluate('min(GS,window=30)')
>>> r
min(GS,window=30)
>>> ts = r.ts()
'''
if isinstance(expression,strtype):
expression = parse(expression)
if not expression or expression.malformed():
raise CouldNotParse(expression)
symbols = expression.symbols()
start = start if not start else todate(start)
end = end if not end else todate(end)
data = providers.load(symbols, start, end, loader = loader,
logger = logger, backend = backend, **kwargs)
return dslresult(expression, data, backend = backend)
def safetodate(dte):
from ccy import todate
try:
return todate(dte)
except:
return None
def test_string(self):
target = date(2014, 1, 5)
self.assertEqual(todate('2014 Jan 05'), target)
def test_string(self):
target = date(2014, 1, 5)
self.assertEqual(todate('2014 Jan 05'), target)
def test_string():
target = date(2014, 1, 5)
assert todate('2014 Jan 05') == target
def safetodate(dte):
try:
return todate(dte)
except:
return None
def safetodate(dte):
try:
return todate(dte)
except:
return None
def test_string():
target = date(2014, 1, 5)
assert todate('2014 Jan 05') == target
def safetodate(dte):
from ccy import todate
try:
return todate(dte)
except:
return None
