Overview

The Unit enumeration identifies common units encountered in STEP data. The zero value indicates an unrecognized unit, and the "as_is" value is used to signal access functions that no unit conversion is desired.

Unit Definition

class Unit(IntEnum):
    UNKNOWN = 0	
    AS_IS	# no conversion

    #  length 
    MM		# millimeters
    CM		# centimeters
    M		# meters
    IN		# inches
    INCH = IN	# alias for convenience
    FT		# feet
    MICROMETRE	# millionth of a meter
    NANOMETRE	# billionth of a meter
    MILLIINCH	# thousandth of an inch
    MICROINCH	# millionth of an inch

    #  area 
    MM2		# square millimeters
    CM2		# square centimeters
    M2		# square meters
    IN2		# square inches
    FT2		# square feet

    #  volume 
    MM3		# cubic millimeters
    CM3		# cubic centimeters
    M3		# cubic meters
    IN3		# cubic inches
    FT3		# cubic feet

    #  angle 
    DEG		# degrees
    RAD		# radians

    #  solid angle 
    STERADIAN	# steradian

    #  time 
    SEC		# seconds
    MIN		# minutes
    HOUR	# hours

    #  feedrates - linear speed 
    MMPS	# millimeters per second
    MMPM	# millimeters per minute
    CMPS	# centimeters per second
    MPS		# meters per second
    IPS		# inches per second
    IPM		# inches per minute
    FPS		# feet per second
    FPM		# feet per minute

    #  feed per revolution 
    MMPREV	# millimeters per revolution
    IPREV	# inches per revolution

    #  feed per tooth 
    MMPTOOTH	# millimeters per tooth
    IPTOOTH	# inches per tooth

    #  spinspeeds - rotational speed 
    HERTZ	# revolutions per second (hz)
    RPM		# revolutions per minute

    #  pressure 
    PA		# pascals
    KPA		# kilopascal
    MPA		# megapascal
    PSI		# pounds per square inch

    #  force 
    NEWTON	# newtons
    LBF		# pound force

    #  power 
    WATT	# watts
    KW		# kilowatts
    HP 		# horsepower

    #  torque - full names to avoid confusion 
    NEWTON_METER  # newton meters
    POUND_FOOT	  # pound foot

    # temperature
    CELSIUS	# degree Celsius
    KELVIN	# degree Kelvin
    FAHRENHEIT	# degree Fahrenheit
    RANKINE	# degree Rankine

    # symbolic units 
    COUNT
    PARAMETER
    RATIO
    REVOLUTION
    TOOTH

    MAX_VALUE

find()

@classmethod
def find(cls, name:str) -> Unit:

The find() function is a class method that returns the enum value for a given string. Both full and abbreviated names are recognized.

print ("FIND foot:", step.Unit.find("foot"))

----------
FIND foot: Unit.FT

fromstep()

@classmethod
def fromstep(cls, obj:step.Object) -> Unit:

The fromstep() function is a class method that returns the enum value for a given STEP unit or measure object. It returns None if the STEP object does not have any unit information.

fullname()

def fullname(self) -> str:

The fullname() function returns the full descriptive name of a unit enum value.

# print full names for every enum value
for nm in sorted(step.Unit.__members__.keys()):
    print (nm, step.Unit[nm].fullname())

----------
AS_IS default
CELSIUS celsius
CM centimetre
CM2 square centimetre
CM3 cubic centimetre
CMPS centimetre/second
COUNT count
DEG degree
... [and so on] ...