使用 % 运算符填充位数

Question

Consider the code:

>>> value = 5
>>> '%02d'%value
'05'

Now instead of hardcoing number of padding digits (in this case 2 ) I want to use another variable for that:

>>> pad = 3

So that now I can get equivalent of:

>>> '%03d'%value
'005'

I could convert to str and use zfill but looking for a more elegant solution.

Answer 1

What version of Python are you using? In modern versions (3.6+) it is very easy to implement using f-strings:

f'{value:0{pad}}'

In earlier versions, you still can use str.format :

'{0:0{1}}'.format(value, pad)