python如何相加加法

Question

#<type 'unicode'>
a = '276.30'
b = '1,446.90'
c = '23,456.80'

相加之后，保留2个小数点~

Answer 1

>>> num=['276.30','1,446.90','23,456.80']
>>> "%.2f" % sum(map(lambda s:float(s.replace(',','')),num))
'25180.00'

---

>>> '{:,.2f}'.format(sum(map(lambda s:float(s.replace(',','')),num)))
'25,180.00'

Answer 2

http://stackoverflow.com/ques...

Answer 3

>>> def sum(*args):
...     r = 0.0
...     for n in args:
...             r += float(n)
...     return "%.2f" % r
...
>>> sum('1.1', '2.2')
'3.30'
>>> sum('1.1', '2.2', 3.3)
'6.60'

Answer 4

It depends on whether you need the displayed value with two decimal places or the real addition with two decimal places.
The former is

ans_print_version = "{.2f}".format(a + b + c)

The latter is

ans = round(a + b + c,2)