Functions for decomposing nonnegative integers according to various unit scales and also parsing support for values written in scales.

Latest release 20250528:

• Big refactor so that we can just str() the result of a decompose.
• New Decomposed, UnitStep, UnitScale classes.

Presupplied scales:

• BINARY_BYTES_SCALE: Binary units of (B)ytes, KiB, MiB, GiB etc.
• DECIMAL_BYTES_SCALE: Decimal units of (B)ytes, KB, MB, GB etc.
• DECIMAL_SCALE: Unit suffixes K, M, G etc.
• TIME_SCALE: Units of (s)econds, (m)inutes, (h)ours, (d)ays and (w)eeks.
• UNSCALED_SCALE: no units

Short summary:

• decimal: Decompose a nonnegative integer n into human decimal counts (kilo etc).
• decompose: Decompose a nonnegative integer n into counts by unit from scale. Returns a Decomposed list of (modulus,UnitStep) in order from smallest unit upward.
• Decomposed: A list of (modulus,UnitStep) 2-tuples representing a decomposed value.
• geek: Decompose a nonnegative integer n into geek bytes sizes (kibibytes etc).
• geek_bytes: Decompose a nonnegative integer n into geek bytes sizes (kibibytes etc).
• human: Decompose a nonnegative integer n into human decimal counts (kilo etc).
• human_bytes: Decompose a nonnegative integer n into human bytes sizes (kilobytes etc).
• human_time: Decompose a nonnegative integer n into human time (hours etc).
• multiparse: Parse an integer followed by an optional scale and return computed value. Returns the parsed value and the new offset.
• parse: Parse an integer followed by an optional scale and return computed value. Returns the parsed value and the new offset. This is a shim for UnitScale.get_term(s,offset).
• transcribe: Transcribe a nonnegative integer n against scale. This is just a shim for UnitScale.transcribe, itself a shim for Decomposed.__str__.
• transcribe_bytes_decompose: Transcribe a nonnegative integer n against DECIMAL_BYTES_SCALE.
• transcribe_bytes_geek: Transcribe a nonnegative integer n against BINARY_BYTES_SCALE.
• transcribe_time: Transcribe a nonnegative integer n against TIME_SCALE.
• UnitScale: A representation of a unit scale as a list of unit terms and scale factors.
• UnitStep: A scale step for a unit scale. The last UnitStep in a scale should have factor=0.

Module contents:

• decimal(n): Decompose a nonnegative integer n into human decimal counts (kilo etc).

• decompose(n, scale: cs.units.UnitScale) -> cs.units.Decomposed: Decompose a nonnegative integer n into counts by unit from scale. Returns a Decomposed list of (modulus,UnitStep) in order from smallest unit upward.

  Parameters:

  • n: a nonnegative integer.
  • scale: a UnitScale (or promotable)

• Class Decomposed(builtins.list)``: A list of (modulus,UnitStep) 2-tuples representing a decomposed value.

Decomposed.__float__(self) -> float: The total value as a float.

Decomposed.__int__(self) -> int: The total value as an int.

Decomposed.__str__(self, max_parts=None, *, skip_zero=False, sep='', no_pad=False) -> str: Transcribe a nonnegative integer n against scale.

Parameters:

• max_parts: the maximum number of components to transcribe.
• skip_zero: omit components of value 0.
• sep: separator between words, default: ''.

Decomposed.sum(self): Return the total value represented by this Decomposed.

• geek(n): Decompose a nonnegative integer n into geek bytes sizes (kibibytes etc).

• geek_bytes(n): Decompose a nonnegative integer n into geek bytes sizes (kibibytes etc).

• human(n): Decompose a nonnegative integer n into human decimal counts (kilo etc).

• human_bytes(n): Decompose a nonnegative integer n into human bytes sizes (kilobytes etc).

• human_time(n): Decompose a nonnegative integer n into human time (hours etc).

• multiparse(s, scales, offset=0): Parse an integer followed by an optional scale and return computed value. Returns the parsed value and the new offset.

  Parameters:

  • s: the string to parse.
  • scales: an iterable of scale arrays of (factor, unit_name).
  • offset: starting position for parse.

• parse(s: str, scale: cs.units.UnitScale, offset=0): Parse an integer followed by an optional scale and return computed value. Returns the parsed value and the new offset. This is a shim for UnitScale.get_term(s,offset).

  Parameters:

  • s: the string to parse.
  • scale: a scale array of (factor, unit_name).
  • offset: starting position for parse.

• transcribe(n, scale: cs.units.UnitScale, max_parts=None, *, skip_zero=False, sep='', no_pad=False): Transcribe a nonnegative integer n against scale. This is just a shim for UnitScale.transcribe, itself a shim for Decomposed.__str__.

  Parameters:

  • n: a nonnegative integer.
  • scale: a UnitScale (or promotable)
  • max_parts: the maximum number of components to transcribe.
  • skip_zero: omit components of value 0.
  • sep: separator between words, default: ''.

• transcribe_bytes_decompose(n, max_parts=1, **kw): Transcribe a nonnegative integer n against DECIMAL_BYTES_SCALE.

• transcribe_bytes_geek(n, max_parts=1, **kw): Transcribe a nonnegative integer n against BINARY_BYTES_SCALE.

• transcribe_time(n, max_parts=3, **kw): Transcribe a nonnegative integer n against TIME_SCALE.

• Class UnitScale(cs.deco.Promotable)``: A representation of a unit scale as a list of unit terms and scale factors.

UnitScale.decompose(self, n) -> cs.units.Decomposed: Decompose a nonnegative integer n into counts by unit. Returns a Decomposed list of (modulus,UnitStep) in order from smallest unit upward.

Parameters:

• n: a nonnegative integer.
• scale: a sequence of UnitStep or (factor,unit[,max_width]) where factor is the size factor to the following scale item and unit is the designator of the unit.

UnitScale.from_str(scale_name: str): Return a UnitScale from its name.

UnitScale.get_term(self, s: str, offset=0) -> Tuple[int, int]: Parse a decimal values possibly followed by a unit name from s at offset. Return a (value,offset) 2-tuple.

Parameters:

• s: the string to parse.
• scale: a scale array of (factor, unit_name).
• offset: starting position for parse.

UnitScale.transcribe(self, n, max_parts=None, *, skip_zero=False, sep='', no_pad=False): Transcribe n according to this scale. Parameters are passed to Decomposed.__str__.

• Class UnitStep``: A scale step for a unit scale. The last UnitStep in a scale should have `factor=0`.

UnitStep.__iter__(self): for unpacking assignment

Release Log

Release 20250528:

• Big refactor so that we can just str() the result of a decompose.
• New Decomposed, UnitStep, UnitScale classes.

Release 20220311: Naming update: rename human* to decompose* to clarify that these decompose a number into a sequence of values on a scale.

Release 20210809: Update parse() for new structure in the scale definitions.

Release 20210717: transcribe: pad units by default, produces less jitter in dynamic displays like progress bars.

Release 20201025: transcribe: use str(count_i), not str(count) if count == count_i.

Release 20200718: Use str.isalpha to recognise "unit" words instead of string.ascii_letters (uses new cs.lex.get_chars "callable gochars" mode).

Release 20200626: transcribe: use "%.1f" to format the count if it is not == int(count) ==> a float-with-fraction.

Release 20200613: New UNSCALED_SCALE for no units.

Release 20190220: Dependency fix.

Release 20181228: Initial PyPI release.