carputils.carpio.quantity.PhysicalQuantity Class Reference

Provides a class to convert physical quantities from a string to numerical values. More...

Public Member Functions
def	__init__ (self, unitdict, iunit, ounit)
def	from_string (self, valuestr, ounit=None)
	Convert a str to numerical value. More...
def	__call__ (self, valuestr)

Properties
	input_unit = property
	Get the default input unit. More...
	output_unit = property
	Get the output unit. More...
	units = property
	Get all the supported units. More...

Detailed Description

Provides a class to convert physical quantities from a string to numerical values.

The PhysicalQuantity class can be used in combination with the ArgumentParser class whenever physical quantities are required as arguments. First you have to define your physical quantity:

# supported units and their scale factors to a reference unit, kPa in this case
unitdict = {'Pa': 0.001, 'kPa': 1.0, 'mPa': 1000.0, 'mmHg': 0.133322387415}
# defualt input unit
iunit = 'kPa'
# output unit
ounit = 'mmHg'
PressureQuantity = PhysicalQuantity(unitdict, iunit, ounit)

Next you can define your argument:

parser.add_argument('--pressure', type=PressureQuantity, default=10.0, ....)

args = parser.parse_args()
# `args.pressure` is of type `float` and already converted to the desired output unit

Now the user can state a pressure with different units:

./script.py --pressure 10.0Pa
./script.py --pressure 10.0kPa
./script.py --pressure 10.0mPa
./script.py --pressure 10.0mmHg
./script.py --pressure 10.0       # No unit, default input unit is used

Defines a physical quantity

Parameters

unitdict	dict A dictionary containing the physical unit and the scale factor to a reference unit
iunit	str The default input unit if not unit is given
ounit	str The output unit

Constructor & Destructor Documentation

__init__()

def carputils.carpio.quantity.PhysicalQuantity.__init__	(		self,
			unitdict,
			iunit,
			ounit
	)

Member Function Documentation

__call__()

def carputils.carpio.quantity.PhysicalQuantity.__call__	(		self,
			valuestr
	)

from_string()

def carputils.carpio.quantity.PhysicalQuantity.from_string	(		self,
			valuestr,
			ounit = None
	)

Convert a str to numerical value.

Parameters

valuestr	str A string representing the physical quantity
ounit	str, optional The desired output unit, if None the default output unit is used

Property Documentation

input_unit

carputils.carpio.quantity.PhysicalQuantity.input_unit = property

static

Get the default input unit.

output_unit

carputils.carpio.quantity.PhysicalQuantity.output_unit = property

static

Get the output unit.

units

carputils.carpio.quantity.PhysicalQuantity.units = property

static

Get all the supported units.

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The documentation for this class was generated from the following file:

• carputils/carpio/quantity.py