reformatting text with comma separated numbers

[anbu23]

>>> import re
>>> pat_obj=re.compile('[0-9,]+')
>>> str='foo 4,566 bar 1,234'
>>>
>>> text=pat_obj.findall(str)
>>> for num in text:
...   str=str.replace(num,num.replace(',','').rjust(len(num),' '))
...
>>> str
'foo  4566 bar  1234'