def test_format_mass(units_in, species_str, spec, output):
# Quantity object can be formatted
qty = registry.Quantity(3.5, units_in)
assert format_mass(qty, species_str, spec) == output
# Unit object can be formatted
qty = registry.Unit(units_in)
assert format_mass(qty, species_str, spec) == output
def convert_gwp(context, qty, to):
"""Helper for :meth:`convert_unit` to perform GWP conversions."""
# Remove a leading 'gwp_' to produce the metric name
metric = context.split('gwp_')[1] if context else context
# Extract the species from *qty* and *to*, allowing supported aliases
species_from, units_from = extract_species(qty[1])
species_to, units_to = extract_species(to)
try:
# Convert using a (magnitude, unit) tuple with only units, and explicit
# input and output units
result = iam_units.convert_gwp(metric, (qty[0], units_from),
species_from, species_to)
except (AttributeError, ValueError):
# Missing *metric*, or *species_to* contains invalid units. pyam
# promises UndefinedUnitError in these cases. Use a subclass (above) to
# add a usage hint.
raise UndefinedUnitError(species_to) from None
except pint.DimensionalityError:
# Provide an exception with the user's inputs
raise pint.DimensionalityError(qty[1], to) from None
# Other exceptions are not caught and will pass up through convert_unit()
if units_to:
# Also convert the units
result = result.to(units_to)
else:
# *to* was only a species name. Provide units based on input and the
# output species name.
to = iam_units.format_mass(result, species_to, spec=':~')
return result, to
def convert_gwp(context, qty, to):
"""Helper for :meth:`convert_unit` to perform GWP conversions."""
# Remove a leading 'gwp_' to produce the metric name
metric = context.split('gwp_')[1]
# Split *to* into a 1- or 3-tuple of str. This allows for *to* to be:
_to = iam_units.emissions.pattern.split(to, maxsplit=1)
if len(_to) == 1:
# Only a species name ('CO2e') without any unit
species_to = _to[0]
units_to = None
else:
# An expression with both units and species name ('kg CO2e / year');
# to[1] is the species
species_to = _to[1]
# Other elements are pre- and suffix, e.g. 'kg ' and ' / year'
units_to = _to[0] + _to[2]
# Convert GWP using the (magnitude, unit-and-species) tuple in *qty*
result = iam_units.convert_gwp(metric, qty, species_to)
if units_to:
# Also convert the units
result = result.to(units_to)
else:
# *to* was only a species name; provide units based on input and the
# output species name
to = iam_units.format_mass(result, species_to, spec=':~')
return result, to
