UnrecognizedUnit#

class astropy.units.UnrecognizedUnit(st, doc=None, format=None, namespace=None)[source]#

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:

ststr: The name of the unit.

Methods Summary

`get_converter`(other[, equivalencies])	Create a function that converts values from this unit to another.
`get_format_name`(format)	Get a name for this unit that is specific to a particular format.
`is_equivalent`(other[, equivalencies])	Returns `True` if this unit is equivalent to `other`.
`is_unity`()	Returns `True` if 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)[source]#

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

Parameters:

otherastropy:unit-like: The unit to convert to.
equivalencieslist of 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:

funccallable(): 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.

get_format_name(format)[source]#

Get a name for this unit that is specific to a particular format.

Uses the dictionary passed into the format kwarg in the constructor.

Parameters:

formatstr: The name of the format

Returns:

namestr: The name of the unit for the given format.

is_equivalent(other, equivalencies=None)[source]#

Returns True if this unit is equivalent to other.

Parameters:

otherUnit, str, or 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.
equivalencieslist of 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()[source]#: Returns True if the unit is unscaled and dimensionless.

to_string(format=None)[source]#

Output the unit in the given format as a string.

Parameters:

formatastropy.units.format.Base instance or str

The name of a format or a formatter object. If not provided, 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
──
s