2nd Shortest Quine in Python ever!

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January 3rd, 2013, 02:07 PM

leonnaley

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2nd Shortest Quine in Python ever!

I think I just thought of the shortest quine for python I think there can ever be! (except a blank program)

make a program with this single line in it

Code:

print(__file__[:-3])

and name the file print(__file__[:-3]).py

and run the file!

any shorter/cooler solutions out there that you know of?

January 3rd, 2013, 02:21 PM

b49P23TIvg

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I'm guessing it actually works. Where? How? When?

Code:

$ python3 print\(__file__[:-3]\).py 
print(__file__[:-3])
Traceback (most recent call last):
  File "print(__file__[:-3]).py", line 1, in <module>
    print(__file__[:-3]).py
AttributeError: 'NoneType' object has no attribute 'py'

It performed worse on python2.
I use linux system.

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January 3rd, 2013, 02:26 PM

leonnaley

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Quote:

Originally Posted by b49P23TIvg

I'm guessing it actually works. Where? How? When?

Code:

$ python3 print\(__file__[:-3]\).py 
print(__file__[:-3])
Traceback (most recent call last):
  File "print(__file__[:-3]).py", line 1, in <module>
    print(__file__[:-3]).py
AttributeError: 'NoneType' object has no attribute 'py'

It performed worse on python2.
I use linux system.

you made a small mistake, leave out the .py part inside the code

January 3rd, 2013, 03:14 PM

Scorpions4ever

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If I leave out the .py, it won't work under linux.

Code:

mb@motorhead:~/python$ python print\(__file__\[\:-3\]\).py 
print(__file__[:-3])

Note that I have to run it with "python name_of_program.py" because .py is not a registered program type like on Windows, so the OS doesn't know what interpreter should be run to interpret .py files. The *nix way is to add this line as the first line in the file:

Code:

#!/usr/bin/python

and then you can run it directly like this

Code:

./print\(__file__\[\:-3\]\).py

Your quine only works if you run it in Windows, with Windows Explorer set to hide file extensions

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January 3rd, 2013, 04:10 PM

leonnaley2

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a quine is supposed to print out its source code, preferably in the least amount of code.

i am running xubuntu, and the program runs in both python 3.2 and python 2.7 on my machine without any problems.

the __file__ is the filename of the file, so __file__[:-3] should eliminate the last three characters from the filename.

the filename should be set to:
print(__file__[:-3]).py

thereby when you print out __file__[:-3] it will print out its own sourcecode which is embedded in the filename.

here is me running my code under linux:

Code:

leon@Leon:/$ python print\(__file__\[\:-3\]\).py 
print(__file__[:-3])
leon@Leon:/$ python2 print\(__file__\[\:-3\]\).py 
print(__file__[:-3])
leon@Leon:/$ python3 print\(__file__\[\:-3\]\).py 
print(__file__[:-3])

yes i have to run the file using the python interpreter, yes i know i could have written #!/usr/bin/python so that linux would know that it should execute this in the python interpreter, but that would ruin my quine, and I dont think its in the quine "rules" that i should have to run it with ./ instead of python2 in front.

i have not tested this in windows though, but it sure works in linux, cant figure out why it shouldn't in yours.

January 3rd, 2013, 04:35 PM

b49P23TIvg

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Well dang, it does work!
Good thinking, congratulations.

Please post at rosettacode.org
or I'll post it for you with credit to you, if you like.

http://rosettacode.org/wiki/Category:Python

http://www.nyx.net/~gthompso/quine.htm

Last edited by b49P23TIvg : January 3rd, 2013 at 04:37 PM. Reason: fix wrong link

January 3rd, 2013, 04:40 PM

leonnaley2

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thanks, i will

it could be even shorter if i limit its use to python 2. i could skip the parantheses then

2nd Shortest Quine in Python ever!

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