| 1 |
1468
|
aaronmk
|
# Quantities with units
|
| 2 |
|
|
# This file's encoding must be UTF-8Y with BOM so Python will auto-detect UTF-8
|
| 3 |
|
|
|
| 4 |
|
|
import re
|
| 5 |
|
|
|
| 6 |
|
|
import format
|
| 7 |
|
|
import strings
|
| 8 |
|
|
import util
|
| 9 |
|
|
|
| 10 |
7655
|
aaronmk
|
def parse_range(str_, range_sep='-'):
|
| 11 |
|
|
default = (str_, None)
|
| 12 |
|
|
start, sep, end = str_.partition(range_sep)
|
| 13 |
|
|
if sep == '': return default # not a range
|
| 14 |
|
|
if start == '' and range_sep == '-': return default # negative number
|
| 15 |
|
|
return tuple(d.strip() for d in (start, end))
|
| 16 |
|
|
|
| 17 |
1468
|
aaronmk
|
class MissingUnitsException(Exception):
|
| 18 |
1476
|
aaronmk
|
def __init__(self, quantity):
|
| 19 |
5700
|
aaronmk
|
Exception.__init__(self, 'Quantity has no units: '
|
| 20 |
|
|
+strings.ustr(quantity))
|
| 21 |
1468
|
aaronmk
|
|
| 22 |
|
|
def std_units(units):
|
| 23 |
|
|
if units == None: return units
|
| 24 |
|
|
else: return strings.remove_suffix('.', units) # for abbr ending in '.'
|
| 25 |
|
|
# TODO: deal with '"° and abbrs
|
| 26 |
|
|
|
| 27 |
1471
|
aaronmk
|
class Quantity:
|
| 28 |
|
|
def __init__(self, value='', units=None):
|
| 29 |
|
|
self.value = value
|
| 30 |
|
|
self.units = std_units(util.none_if(units, u''))
|
| 31 |
|
|
|
| 32 |
|
|
def quantity2str(quantity):
|
| 33 |
|
|
str_ = quantity.value
|
| 34 |
|
|
if quantity.units != None: str_ += ' '+quantity.units
|
| 35 |
|
|
return str_
|
| 36 |
|
|
|
| 37 |
|
|
Quantity.__str__ = quantity2str
|
| 38 |
1566
|
aaronmk
|
Quantity.__repr__ = quantity2str
|
| 39 |
1471
|
aaronmk
|
|
| 40 |
|
|
def str2quantity(str_):
|
| 41 |
|
|
value = str_
|
| 42 |
1468
|
aaronmk
|
units = None
|
| 43 |
1471
|
aaronmk
|
if not str_.isdigit(): # optimization to avoid regexp for simple cases
|
| 44 |
1566
|
aaronmk
|
match = re.match(ur'(?i)^\s*(.*?\d\.?)\s*([a-z%\'"°][\w.*/^-]*?)?\s*$',
|
| 45 |
1471
|
aaronmk
|
str_)
|
| 46 |
|
|
if match: value, units = match.groups() # has units
|
| 47 |
|
|
return Quantity(value, units)
|
| 48 |
1468
|
aaronmk
|
|
| 49 |
1471
|
aaronmk
|
def set_default_units(quantity, units):
|
| 50 |
|
|
if quantity.units == None: quantity.units = units
|
| 51 |
|
|
|
| 52 |
1566
|
aaronmk
|
conversions = {
|
| 53 |
7654
|
aaronmk
|
('%', None): 1./100,
|
| 54 |
|
|
('ft', 'm'): 12*2.54/100,
|
| 55 |
1566
|
aaronmk
|
}
|
| 56 |
|
|
|
| 57 |
1471
|
aaronmk
|
def convert(quantity, units):
|
| 58 |
|
|
units = std_units(units)
|
| 59 |
1565
|
aaronmk
|
if quantity.units == units: return quantity # units already correct
|
| 60 |
1566
|
aaronmk
|
try: conversion = conversions[(quantity.units, units)]
|
| 61 |
|
|
except KeyError:
|
| 62 |
|
|
if units == None: return Quantity(quantity.value, units) # remove units
|
| 63 |
|
|
elif quantity.units == None: raise MissingUnitsException(quantity)
|
| 64 |
|
|
# can't convert quantity with unknown units
|
| 65 |
|
|
else: raise NotImplementedError('Unit conversion not implemented yet')
|
| 66 |
|
|
else:
|
| 67 |
|
|
return Quantity(str(format.str2float(quantity.value)*conversion), units)
|
