UnrecognizedUnit

class astropy.units.UnrecognizedUnit(st, doc=None, format=None, namespace=None)

Bases: IrreducibleUnit

A unit that did not parse correctly. This allows for round-tripping it as a string, but no unit operations actually work on it.

Parameters:

stpython:str

The name of the unit.

Methods Summary

get_converter(other[, equivalencies])	Create a function that converts values from this unit to another.
is_equivalent(other[, equivalencies])	Check whether this unit is equivalent to other.
is_unity()	Check whether the unit is unscaled and dimensionless.
to_string([format])	Output the unit in the given format as a string.

Methods Documentation

get_converter(other, equivalencies=None)

Create a function that converts values from this unit to another.

Parameters:

otherastropy:unit-like

The unit to convert to.

equivalenciespython:list of python:tuple

A list of equivalence pairs to try if the units are not directly convertible. See Equivalencies. This list is in addition to possible global defaults set by, e.g., set_enabled_equivalencies. Use None to turn off all equivalencies.

Returns:

funcpython:callable()

A callable that takes an array-like argument and returns it converted from units of self to units of other.

Raises:

UnitsError

If the units cannot be converted to each other.

Notes

This method is used internally in Quantity to convert to different units. Note that the function returned takes and returns values, not quantities.

is_equivalent(other, equivalencies=None)

Check whether this unit is equivalent to other.

Parameters:

otherUnit, python:str, or python:tuple

The unit to convert to. If a tuple of units is specified, this method returns true if the unit matches any of those in the tuple.

equivalenciespython:list of python:tuple

A list of equivalence pairs to try if the units are not directly convertible. See Equivalencies. This list is in addition to possible global defaults set by, e.g., set_enabled_equivalencies. Use None to turn off all equivalencies.

Returns:

bool

is_unity() → Literal[False]

Check whether the unit is unscaled and dimensionless.

to_string(format=None)

Output the unit in the given format as a string.

Parameters:

formatastropy.units.format.Base subclass or python:str or python:None

The name of a format or a formatter class. If not provided (or None), defaults to the generic format.

**kwargs

Further options forwarded to the formatter. Currently recognized is fraction, which can take the following values:

• False : display unit bases with negative powers as they are;

• ‘inline’ or True : use a single-line fraction;

• ‘multiline’ : use a multiline fraction (available for the ‘latex’, ‘console’ and ‘unicode’ formats only).

Raises:

TypeError

If format is of the wrong type.

ValueError

If format or fraction are not recognized.

Examples

>>> import astropy.units as u
>>> kms = u.Unit('km / s')
>>> kms.to_string()  # Generic uses fraction='inline' by default
'km / s'
>>> kms.to_string('latex')  # Latex uses fraction='multiline' by default
'$\\mathrm{\\frac{km}{s}}$'
>>> print(kms.to_string('unicode', fraction=False))
km s⁻¹
>>> print(kms.to_string('unicode', fraction='inline'))
km / s
>>> print(kms.to_string('unicode', fraction='multiline'))
km
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s