Python String Formatter having %

Question

It's simple when the string is something like:

s = 'test%s1'
s % 'TEST'

However, when % itself is present in the string, then I'm getting this error. eg:

s = 'test%s12%34'
s % 'TEST'
>>ValueError: incomplete format

How to handel this case ??

Martijn Pieters · Accepted Answer · 2014-11-06 08:27:33Z

7

Double the %:

s = 'test%s12%%34'

On output it'll be collapsed again to a single percent symbol:

>>> s = 'test%s12%%34'
>>> s % 'TEST'
'testTEST12%34'

From the String Formatting Operations documentation, where the various conversion characters are documented:

'%' No argument is converted, results in a '%' character in the result.

where the second % is the conversion character.

answered Nov 6, 2014 at 8:27

Martijn Pieters

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2 Comments

Cool !! Can you also explain the reason behind its working ??

@SaurabhVerma: it is a documented conversion character; %% is converted to %.