Python "ValueError: incomplete format" upon print("stuff %" % "thingy")

Question

My goal with this code is that when you put in a certain number, you will get printed the number and some other output, based on what you typed. For some reason, what I have here gives the error "ValueError: incomplete format". It has something to do with the %. What does the error mean, and how do I fix it? Thanks!

variable = "Blah"
variable2 = "Blahblah"

text = raw_input("Type some stuff: ")

if "1" in text:
    print ("One %" % variable)
elif "2" in text:
    print ("Two %" % variable2)

Possible duplicate of [How can I selectively escape percent (%) in Python strings?](http://stackoverflow.com/questions/10678229/how-can-i-selectively-escape-percent-in-python-strings) — Aurora0001, Jan 13 '17 at 18:16

Chad S. · Accepted Answer · 2021-03-18T22:35:42.783

24

Python is expecting another character to follow the % in the string literal to tell it how to represent variable in the resulting string.

Instead use

"One %s" % (variable,)

or

"One {}".format(variable)

to create a new string where the string representation of variable is used instead of the placeholder.

edited Mar 18 '21 at 22:35

answered Jan 07 '16 at 22:28

Chad S.

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Here is the [Python documentation on this](https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting) and also a [very nice tutorial](http://www.python-course.eu/python3_formatted_output.php). The tutorial also describes the newer, [``format()`` style of formatting](https://docs.python.org/3/library/string.html#format-string-syntax), but the older ``%`` style is still much used because, although less powerful, it is often more convenient. – Lutz Prechelt Apr 12 '16 at 09:14

score 13 · Answer 2 · answered Jan 13 '17 at 10:30

13

>>> variable = "Blah"
>>> '%s %%' % variable
    'Blah %'
>>>

answered Jan 13 '17 at 10:30

Ravi Gadhia

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Curious, what version of python did you use for this to work, 3x or 2x? (I am using 2.7.13, where it does not seem to work) – ryyker Jan 13 '17 at 17:53
@ryyker, I just tested with Python 3.5.2 - works fine. As far as I can tell it *should* also work for 2.7, according to [this](http://stackoverflow.com/questions/10678229/how-can-i-selectively-escape-percent-in-python-strings). – Aurora0001 Jan 13 '17 at 18:16
this doesn't really answer the question but actually solves the problem I had when stumbling upon this question – pocpoc47 Mar 28 '17 at 08:46

score 1 · Answer 3 · edited Jan 07 '16 at 22:30

1

an easy way:

print ("One " + variable)

edited Jan 07 '16 at 22:30

donkopotamus

22,114
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answered Jan 07 '16 at 22:29

ᴀʀᴍᴀɴ

4,443
8
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1

Or just `print("One", variable)` which works for both strings and non strings, but only in Python 3.x – Artyer Jan 07 '16 at 22:32

Python "ValueError: incomplete format" upon print("stuff %" % "thingy")

3 Answers3