Python四舍五入为两位数

Question

Below is the code:

if number_of_bytes < 0:
    raise ValueError("!!! numberOfBytes can't be smaller than 0 !!!")
step_to_greater_unit = 1024.
number_of_bytes = float(number_of_bytes)
unit = 'bytes'
if (number_of_bytes / step_to_greater_unit) >= 1:
    number_of_bytes /= step_to_greater_unit
    unit = 'KB'
if (number_of_bytes / step_to_greater_unit) >= 1:
    number_of_bytes /= step_to_greater_unit
    unit = 'MB'
if (number_of_bytes / step_to_greater_unit) >= 1:
    number_of_bytes /= step_to_greater_unit
    unit = 'GB'
if (number_of_bytes / step_to_greater_unit) >= 1:
    number_of_bytes /= step_to_greater_unit
    unit = 'TB'
precision = 3
number_of_bytes = round(number_of_bytes, precision)
print number_of_bytes
size = str(number_of_bytes) + '' + unit

Below is the sample output:

 1.125TB


 1.406TB

Expected output:

 1.12TB


 1.41TB

when my precision value is 2 I am getting 1.13TB but I need to round off to 1.12TB .

Basically 1.125TB I need two decimal points. 1.125 is rounding off to 1.13 but it should round of to 1.12 and 1.406TB should round off to 1.41TB

Could you please help how to get my expected result

Answer 1

Would suggest you to look into the hurry package, which eases things a bit when it comes to file size prints.

>>> from hurry.filesize import alternative
>>> size(1, system=alternative)
'1 byte'
>>> size(10, system=alternative)
'10 bytes'
>>> size(1024, system=alternative)
'1 KB'

https://pypi.python.org/pypi/hurry.filesize