Unit Definitions
Philote's unit system overlaps with that of OpenMDAO. The main difference is that the lack of units cannot be specified using the None type in Python. Instead it should be listed as unitless.
The currently defined units are listed here (taken from the OpenMDAO documentation, licensed under the Apache 2 license):
# Default unit library definitions. Much of this is based on
# http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf
# ------------------------------------------------------------------------
[prefixes]
# ------------------------------------------------------------------------
# prefix-string: float-multiplier [, comment]
# SI.
Y: 1.e24
Z: 1.e21
E: 1.e18
P: 1.e15
T: 1.e12
G: 1.e9
M: 1.e6
k: 1.e3
h: 1.e2
da: 1.e1
d: 1.e-1
c: 1.e-2
m: 1.e-3
u: 1.e-6
n: 1.e-9
p: 1.e-12
f: 1.e-15
a: 1.e-18
z: 1.e-21
y: 1.e-24
# IEC
Ei: 1152921504606846976, (1 << 60)
Pi: 1125899906842624, (1 << 50)
Ti: 1099511627776, (1 << 40)
Gi: 1073741824, (1 << 30)
Mi: 1048576, (1 << 20)
Ki: 1024, (1 << 10)
# ------------------------------------------------------------------------
[base_units]
# ------------------------------------------------------------------------
# quantity-name: unit-name
# SI.
length: m
mass: kg
time: s
current: A
temperature: K
amount: mol
luminous_intensity: cd
# Derived SI (Table 3).
angle: rad
solid_angle: sr
# Other.
money: USD
passengers: pax
digital_data: byte
# Unitness
Unitless: unitless
# ------------------------------------------------------------------------
[units]
# ------------------------------------------------------------------------
# unit-name: unit-expression, comment
# OR
# unit-name: factor, base-unit, offset, comment
#
# Note that unit names cannot be Python reserved words (such as 'in' for inch).
# Unit names are matched before prefix names are checked.
# A unit-expression cannot use prefixes (except for 'kg'), however 'pi' is
# available as a predefined constant.
g: kg/1000, gram
# Derived SI (Table 3).
Hz: 1/s, hertz
N: m*kg/s**2, newton
Pa: N/m**2, pascal
J: N*m, joule
W: J/s, watt
C: A*s, coulomb
V: W/A, volt
F: C/V, farad
ohm: V/A, ohm
S: A/V, siemens
Wb: V*s, weber
T: Wb/m**2, tesla
H: Wb/A, henry
degC: 1, K, 273.15, degree celsius
lm: cd*sr, lumen
lx: lm/m**2, lux
Bq: 1/s, becquerel
Gy: J/kg, gray
Sv: J/kg, sievert
kat: mol/s, katal
# Non-SI (Table 6).
min: 60*s, minute
h: 3600*s, hour
d: 86400*s, day
deg: (pi/180)*rad, degree
arc_minute: deg/60, arc minute
arc_second: arc_minute/60, arc second
ha: 1e4*m**2, hectare
L: 1e-3*m**3, liter
t: 1e3*kg, tonne (metric ton)
# Non-SI (Table 7).
e: 1.60217653e-19*C, elementary charge
eV: e*V, electron volt
Da: 1.66053886e-27*kg, dalton
u: Da, unified atomic mass unit
ua: 1.49597870700e11*m, astronomical unit
AU: 1.49597870700e11*m, astronomical unit
c0: 299792458.*m/s, speed of light in vacuum
hbar: 1.05457168e-34*J*s, reduced Planck Constant
me: 9.1093826e-31*kg, electron mass
a0: 0.5291772108e-10*m, Bohr radius
Eh: 4.35974417e-18*J, Hartree energy
# Non-SI (Table 8).
bar: 1.e5*Pa, pressure
Ang: 1.e-10*m, angstrom
NM: 1.852e3*m, nautical mile
b: 1.e-28*m**2, barn
kn: NM/h, knot
# Non-SI (Table 9).
erg: 1.e-7*J, erg
dyn: 1.e-5*N, dyne
P: 0.1*Pa*s, poise (dynamic viscosity)
St: 1.e-4*m**2/s, stokes (kinematic viscosity)
sb: 1.e4*cd/m**2, stilb (luminance)
ph: 1.e4*lx, phot (illuminance)
# 'Gal' skipped due to likely confusion with volume unit.
Mx: 1.e-8*Wb, maxwell (magnetic flux)
# 'G' renamed 'gauss' to avoid confusion with acceleration unit.
gauss: 1e-4*T, gauss (magnetic flux density)
Oe: (1.e3/(4*pi))*A/m, oersted (magnetic field)
# Backward compatibility.
degK: K, degree Kelvin
nmi: NM, nautical mile
knot: kn, knot
# Other length.
inch: 2.54e-2*m, inch
ft: 0.3048*m, foot
mi: 1.609344e3*m, mile (U.S. statute)
ly: c0*365.25*d, light year
pc: 648000/pi*AU, parsec
# Other mass.
oz: 28.349523125*g, ounce
lb: 16*oz, pound mass
lbm: lb, pound mass
ton: 2000*lb, ton (short)
slug: 14.5939029*kg, slug
# Other time.
wk: 7*d, week
week: 7*d, week (backward compatibility)
a: 365.242199*d, year
yr: a, year
year: a, year (backward compatibility)
mo: yr/12, month
month: yr/12, month (backward compatibility)
# Other temperature.
degR: K*5./9., degree Rankine
degF: 1, degR, 459.67, degree Fahrenheit
# Other volume.
tsp: 4.92892159375e-3*L, teaspoon
tbsp: 3*tsp, tablespoon
floz: 2*tbsp, fluid ounce
cup: 8*floz, cup
pt: 16*floz, pint
qt: 2*pt, quart
galUS: 3.785411*L, gallon (U.S.)
galUK: 4.54609*L, gallon (U.K.)
# Other miscellaneous.
lbf: 4.44822162*N, pound force
rev: 2*pi*rad, revolution
rpm: 2*pi*rad/min, RPM
rps: 2*pi*rad/s, RPS
cal: 4.184*J, thermochemical calorie
cali: 4.1868*J, international calorie
Btu: 1055.05585262*J, British thermal unit
acre: mi**2/640, acre
hp: 745.7*W, horsepower
atm: 101325.*Pa, standard atmosphere
torr: atm/760, Torr (1 mm of mercury)
psi: 6894.75729317*Pa, pounds per square inch
psf: psi/144, pounds per square foot
mu0: 4.e-7*pi*N/A**2, permeability of vacuum
eps0: 1/mu0/c0**2, permittivity of vacuum
Grav: 6.67259e-11*m**3/kg/s**2, universal gravitational constant
Nav: 6.0221367e23/mol, Avagadros number
R: 8.31424*J/(mol*K), gas constant
V0: 2.24136*m**3/(1000*mol), volume of ideal gas
planck: 2*pi*hbar, Planck constant
mp: 1.672614e-27*kg, proton rest mass
mn: 1.674920e-27*kg, neutron rest mass
sigma: 5.66961e-8*W/(m**2*K**-4), Stefan-Boltzmann constant
Ken: 1.380649e-23*J, kelvin as energy unit
Rinfinity: 1.09737312e7/m, Rydberg constant
re: 2.817939e-15*m, classic electron radius
lambdac: 2.4263096e-12*m, Compton wavelength of electron
lambdap: 1.3214409e-15*m, Compton wavelength of proton
lambdan: 1.3196217e-15*m, Compton wavelength of neutron
mue: 9.284851e-24*J/T, electron magnetic moment
mup: 1.4106203e-26*J/T, proton magnetic moment
mub: 9.274096e-24*J/T, bohr magneton
mun: 5.050951e-27*J/T, nuclear magneton
gammap: 2.6751270e8*rad/(s*T), gyromagnetic ratio of protons in H2O
gammapc: 2.6751965e8*rad/(s*T), gyromagnetic ratio of protons in H2O corrected for diamagnetism of H2O
phi0: 2.0678538e-15*Wb, magnetic flux quantum
hme: 7.273894e-4*J*s/kg, quantum of circulation
percent: unitless/100, percentage