3.75 + 8.2 - 4.93 + 7.875 - 3.45 + 15.6 + 123.45 -...

python
from decimal import Decimal, getcontext
getcontext().prec = 28

expr = """
3.75 + 8.2 - 4.93 + 7.875 - 3.45 + 15.6 + 123.45 - 67.89 + 54.32 - 0.78 + 20.125 - 9.008 + 100.1 - 99.99 + 5.55 - 9.008 + 6.66 - 18.72 + 9.8 - 0.305 + 123.45 - 67.89 + 45 - 12.345 + 7.89 - 89.6 + 0.001 - 23.45 + 11.11 - 67.8 + 0.78 + 90.12 - 80 + 36.78 - 1.234 + 50 + 1.01 - 0.99 + 7.654 - 2.3 - 1.01 + 34.56 - 78.9 + 100.1 - 99.99 + 7.654 - 5.55 + 6.66 - 18.72 + 9.8 - 34.56 + 0.305 - 12.7 + 45 - 12.345 - 100.1 - 7.89 + 0.001 - 23.45 + 11.11 - 5.55 + 67.8 - 90.12 + 80 - 36.78 - 18.72 - 1.234 + 3.75 + 8.2 - 4.93 - 0.305 + 7.875 - 3.45 - 15.6 + 123.45 - 67.89 + 54.32 - 0.78 - 45 - 67.89 + 54.32 - 0.78 + 9.008 - 7.89 + 100.1 - 99.99 + 5.55 - 18.72 - 23.45 - 9.8 + 0.305 - 45 + 12.345 - 67.8 + 0.001 - 23.45 + 11.11 - 67.8 - 80 + 36.78 - 1.234 + 3.75 + 8.2 - 4.93
"""
# parse expression into terms with signs
import re
tokens = re.findall(r'[+-]\s*\d+(?:\.\d+)?|^\s*\d+(?:\.\d+)?', expr)
total = Decimal('0')
for tok in tokens:
    tok = tok.strip()
    # ensure explicit sign
    if tok[0] in '+-':
        val = Decimal(tok.replace(' ', ''))
    else:
        val = Decimal(tok.replace(' ', ''))
    total += val
total


Decimal('-232.719')

python
from decimal import Decimal, getcontext
getcontext().prec = 28
terms = [
Decimal('3.75'), Decimal('8.2'), Decimal('-4.93'), Decimal('7.875'), Decimal('-3.45'),
Decimal('15.6'), Decimal('123.45'), Decimal('-67.89'), Decimal('54.32'), Decimal('-0.78'),
Decimal('20.125'), Decimal('-9.008'), Decimal('100.1'), Decimal('-99.99'), Decimal('5.55'),
Decimal('-9.008'), Decimal('6.66'), Decimal('-18.72'), Decimal('9.8'), Decimal('-0.305'),
Decimal('123.45'), Decimal('-67.89'), Decimal('45'), Decimal('-12.345'), Decimal('7.89'),
Decimal('-89.6'), Decimal('0.001'), Decimal('-23.45'), Decimal('11.11'), Decimal('-67.8'),
Decimal('0.78'), Decimal('90.12'), Decimal('-80'), Decimal('36.78'), Decimal('-1.234'),
Decimal('50'), Decimal('1.01'), Decimal('-0.99'), Decimal('7.654'), Decimal('-2.3'),
Decimal('-1.01'), Decimal('34.56'), Decimal('-78.9'), Decimal('100.1'), Decimal('-99.99'),
Decimal('7.654'), Decimal('-5.55'), Decimal('6.66'), Decimal('-18.72'), Decimal('9.8'),
Decimal('-34.56'), Decimal('0.305'), Decimal('-12.7'), Decimal('45'), Decimal('-12.345'),
Decimal('-100.1'), Decimal('-7.89'), Decimal('0.001'), Decimal('-23.45'), Decimal('11.11'),
Decimal('-5.55'), Decimal('67.8'), Decimal('-90.12'), Decimal('80'), Decimal('-36.78'),
Decimal('-18.72'), Decimal('-1.234'), Decimal('3.75'), Decimal('8.2'), Decimal('-4.93'),
Decimal('-0.305'), Decimal('7.875'), Decimal('-3.45'), Decimal('-15.6'), Decimal('123.45'),
Decimal('-67.89'), Decimal('54.32'), Decimal('-0.78'), Decimal('-45'), Decimal('-67.89'),
Decimal('54.32'), Decimal('-0.78'), Decimal('9.008'), Decimal('-7.89'), Decimal('100.1'),
Decimal('-99.99'), Decimal('5.55'), Decimal('-18.72'), Decimal('-23.45'), Decimal('-9.8'),
Decimal('0.305'), Decimal('-45'), Decimal('12.345'), Decimal('-67.8'), Decimal('0.001'),
Decimal('-23.45'), Decimal('11.11'), Decimal('-67.8'), Decimal('-80'), Decimal('36.78'),
Decimal('-1.234'), Decimal('3.75'), Decimal('8.2'), Decimal('-4.93')
]
sum(terms)

Decimal('-232.719')

python
from decimal import Decimal, getcontext
getcontext().prec = 28
expr = """3.75 + 8.2 - 4.93 + 7.875 - 3.45 + 15.6 + 123.45 - 67.89 + 54.32 - 0.78 + 20.125 - 9.008 + 100.1 - 99.99 + 5.55 - 9.008 + 6.66 - 18.72 + 9.8 - 0.305 + 123.45 - 67.89 + 45 - 12.345 + 7.89 - 89.6 + 0.001 - 23.45 + 11.11 - 67.8 + 0.78 + 90.12 - 80 + 36.78 - 1.234 + 50 + 1.01 - 0.99 + 7.654 - 2.3 - 1.01 + 34.56 - 78.9 + 100.1 - 99.99 + 7.654 - 5.55 + 6.66 - 18.72 + 9.8 - 34.56 + 0.305 - 12.7 + 45 - 12.345 - 100.1 - 7.89 + 0.001 - 23.45 + 11.11 - 5.55 + 67.8 - 90.12 + 80 - 36.78 - 18.72 - 1.234 + 3.75 + 8.2 - 4.93 - 0.305 + 7.875 - 3.45 - 15.6 + 123.45 - 67.89 + 54.32 - 0.78 - 45 - 67.89 + 54.32 - 0.78 + 9.008 - 7.89 + 100.1 - 99.99 + 5.55 - 18.72 - 23.45 - 9.8 + 0.305 - 45 + 12.345 - 67.8 + 0.001 - 23.45 + 11.11 - 67.8 - 80 + 36.78 - 1.234 + 3.75 + 8.2 - 4.93"""
import re
# normalize: replace unicode spaces? none.
nums = re.findall(r'([+\-]?)\s*(\d+(?:\.\d+)?)', expr)
total = Decimal('0')
sign=1
# We'll process tokens with preceding operator if present or plus by default
# Actually regex returns both; we need to iterate on numbers in order with their sign if preceded by operator token; But since we captured grouping for each token including plus/minus not only when separated. However numbers also detected after spaces; This approach matches both numbers and sign preceding them but includes empty sign for first number. That works.
for s, n in nums:
    if s == '-':
        total -= Decimal(n)
    else:
        total += Decimal(n)
total

Decimal('-232.719')

python
from decimal import Decimal, getcontext
getcontext().prec=50
terms = [Decimal(x) for x in [
'3.75','8.2','-4.93','7.875','-3.45','15.6','123.45','-67.89','54.32','-0.78','20.125','-9.008','100.1','-99.99','5.55','-9.008','6.66','-18.72','9.8','-0.305','123.45','-67.89','45','-12.345','7.89','-89.6','0.001','-23.45','11.11','-67.8','0.78','90.12','-80','36.78','-1.234','50','1.01','-0.99','7.654','-2.3','-1.01','34.56','-78.9','100.1','-99.99','7.654','-5.55','6.66','-18.72','9.8','-34.56','0.305','-12.7','45','-12.345','-100.1','-7.89','0.001','-23.45','11.11','-5.55','67.8','-90.12','80','-36.78','-18.72','-1.234','3.75','8.2','-4.93','-0.305','7.875','-3.45','-15.6','123.45','-67.89','54.32','-0.78','-45','-67.89','54.32','-0.78','9.008','-7.89','100.1','-99.99','5.55','-18.72','-23.45','-9.8','0.305','-45','12.345','-67.8','0.001','-23.45','11.11','-67.8','-80','36.78','-1.234','3.75','8.2','-4.93'
]]
total = sum(terms)
scaled = sum(int((t*1000).to_integral_exact()) for t in terms)
Decimal(scaled)/Decimal(1000), total


(Decimal('-232.719'), Decimal('-232.719'))

python
from decimal import Decimal
terms = [
Decimal('3.75'), Decimal('8.2'), Decimal('-4.93'), Decimal('7.875'), Decimal('-3.45'),
Decimal('15.6'), Decimal('123.45'), Decimal('-67.89'), Decimal('54.32'), Decimal('-0.78'),
Decimal('20.125'), Decimal('-9.008'), Decimal('100.1'), Decimal('-99.99'), Decimal('5.55'),
Decimal('-9.008'), Decimal('6.66'), Decimal('-18.72'), Decimal('9.8'), Decimal('-0.305'),
Decimal('123.45'), Decimal('-67.89'), Decimal('45'), Decimal('-12.345'), Decimal('7.89'),
Decimal('-89.6'), Decimal('0.001'), Decimal('-23.45'), Decimal('11.11'), Decimal('-67.8'),
Decimal('0.78'), Decimal('90.12'), Decimal('-80'), Decimal('36.78'), Decimal('-1.234'),
Decimal('50'), Decimal('1.01'), Decimal('-0.99'), Decimal('7.654'), Decimal('-2.3'),
Decimal('-1.01'), Decimal('34.56'), Decimal('-78.9'), Decimal('100.1'), Decimal('-99.99'),
Decimal('7.654'), Decimal('-5.55'), Decimal('6.66'), Decimal('-18.72'), Decimal('9.8'),
Decimal('-34.56'), Decimal('0.305'), Decimal('-12.7'), Decimal('45'), Decimal('-12.345'),
Decimal('-100.1'), Decimal('-7.89'), Decimal('0.001'), Decimal('-23.45'), Decimal('11.11'),
Decimal('-5.55'), Decimal('67.8'), Decimal('-90.12'), Decimal('80'), Decimal('-36.78'),
Decimal('-18.72'), Decimal('-1.234'), Decimal('3.75'), Decimal('8.2'), Decimal('-4.93'),
Decimal('-0.305'), Decimal('7.875'), Decimal('-3.45'), Decimal('-15.6'), Decimal('123.45'),
Decimal('-67.89'), Decimal('54.32'), Decimal('-0.78'), Decimal('-45'), Decimal('-67.89'),
Decimal('54.32'), Decimal('-0.78'), Decimal('9.008'), Decimal('-7.89'), Decimal('100.1'),
Decimal('-99.99'), Decimal('5.55'), Decimal('-18.72'), Decimal('-23.45'), Decimal('-9.8'),
Decimal('0.305'), Decimal('-45'), Decimal('12.345'), Decimal('-67.8'), Decimal('0.001'),
Decimal('-23.45'), Decimal('11.11'), Decimal('-67.8'), Decimal('-80'), Decimal('36.78'),
Decimal('-1.234'), Decimal('3.75'), Decimal('8.2'), Decimal('-4.93')
]
total = sum(terms)
scaled = sum(int((t*1000).to_integral_exact()) for t in terms)
total, Decimal(scaled)/Decimal(1000)


(Decimal('-232.719'), Decimal('-232.719'))