问题描述
我一直在编写一个脚本，该脚本从 Excel 电子表格中获取数据，对数字进行四舍五入并删除小数点，例如，2606.89579999999 变为 26069.但是，我需要将数字四舍五入到小数点后两位后面会有一个零，所以 2606.89579999999 应该变成 260690.
I've been working on a script that takes data from an Excel spreadsheet, rounds the numbers, and removes the decimal point, for example, 2606.89579999999 becomes 26069. However, I need the number to round to two decimal places even if there would be a trailing zero, so 2606.89579999999 should become 260690.
我目前有它，所以 i 从 Excel 中的单元格中获取数据，并将其四舍五入到小数点后两位 (i = round(i, 2))在上面的例子中给了我一个小数点.
I currently have it so i takes the data from the cell in Excel, and rounds it to two decimal places (i = round(i, 2)) which gives me the single decimal point in the above example.
我已经尝试弄清楚如何让它与 Decimal 一起工作，但我似乎无法让它工作.
I've tried figuring out how to get this to work with Decimal, but I can't seem to get it working.
所有其他四舍五入的数字，如果四舍五入的值不以0"结尾，则可以使用 round(i, 2)，但如果数字恰好以*.x0，那个 0 被丢弃并与数据混淆.
All other numbers that get rounded, if the rounded value doesn't end in '0', work fine with round(i, 2), but if the numbers just so happen to end in *.x0, that 0 gets dropped off and messes with the data.
推荐答案
正如你所说的尾随零，这是一个关于表示为字符串的问题，你可以使用
As you are talking about trailing zeros, this is a question about representation as string, you can use
>>> "%.2f" % round(2606.89579999999, 2)
'2606.90'
或者使用带有format功能的现代风格:
Or use modern style with format function:
>>> '{:.2f}'.format(round(2606.89579999999, 2))
'2606.90'
并用 replace 或 translate 删除点(_ 指 python 控制台中先前命令的结果):
and remove point with replace or translate (_ refers to result of previous command in python console):
>>> _.translate(None, '.')
'260690'
注意这里不需要四舍五入，因为 .2f 格式应用相同的四舍五入:
Note that rounding is not needed here, as .2f format applyies the same rounding:
>>> "%.2f" % 2606.89579999999
'2606.90'
但正如您提到的 excel，您可能会选择滚动自己的舍入函数，或使用 decimal，因为 float.round 会由于浮点表示而导致奇怪的结果:
But as you mentioned excel, you probably would opt to roll your own rounding function, or use decimal, as float.round can lead to strange results due to float representation:
>>> round(2.675, 2)
2.67
>>> round(2606.89579999999, 2)
2606.89
使用小数量化:
>>> from decimal import *
>>> x = Decimal('2606.8950000000001')
# Decimal('2606.8950000000001')
>>> '{}'.format(x.quantize(Decimal('.01'), rounding=ROUND_HALF_EVEN))
'2606.90'
对于您的原始任务，变为:
That, for your original task, becomes:
>>> x = Decimal('2606.8950000000001')
>>> int((x*100).quantize(1, rounding=ROUND_HALF_EVEN))
260690
Decimal 出现了奇怪的四舍五入的原因:
And the reason of strange rounding comes to the front with Decimal:
>>> x = Decimal(2606.8950000000001)
# Decimal('2606.89499999999998181010596454143524169921875') # internal float repr
这篇关于在 Python 中舍入一个数字但保持结尾为零的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！