Python quine

A quine is a program that provides its own source code as output.

A quine program , or quine , is a program that outputs its own source code when run. Instead, it must compute its own source code. The trick is getting the string just right. How you do this varies from language to language depending on how variables are declared, the method of interpolation, the possible need for semicolons and newlines, the kinds of quotes required, and so on. Dealing with quotes is interesting; you need to find a way to specify that a quote character is to be printed without actually using a quote character. Note : In each of the following examples, the programs are assumed to have no newline at the end of the program text unless specified.

Python quine

This post is a few years old now, so some details or my opinions might be out of date. I would still love to hear your feedback in the comments below. A self printing program is, as is its name, self explanatory. Today I thought about how to implement a quine in Python, I whipped up a solution on my own and then posed the challenge to some people in the office. These are the results:. This exemplifies a common way to implement a quine - the main problem is that you have to use some sort of function that prints. But of course, you also have to print that function, and so on. The way to deal with this is put the entire program in a string, except the assignment to that string, then print the assignment where you can use the string itself to avoid explicitly writing it again, thus avoiding the recursion , and then the string. Next is a version that tries to solve this. This version while a bit cumbersome solves the quotation marks problem by just explicitly printing the ascii characters.

We have discussed quine in C. Article Talk. It doesn't print python quine entire representation, but it does rely on the the fact that functions have a particular representation.

I wouldn't say this is the most boring. In Python it is certainly an empty file. It was interesting to see the author work through the major obstacles one by one when writing a quine. Glad they didn't take the actual boring route! I wish the article talked about "the most boring nonempty quine".

Released: Jun 16, View statistics for this project via Libraries. This implementation of the Quine McCluskey algorithm has no inherent limits other than the calculation time on the size of the inputs. Also, in the limited tests of the author of this module, this implementation is considerably faster than other public Python implementations for non-trivial inputs. This slows down the algorithm, but in some cases the result can be much more compact than a sum of product. Jun 16, Jan 3, Dec 9, Download the file for your platform.

Python quine

A quine is a computer program that takes no input and produces a copy of its own source code as its only output. The standard terms for these programs in the computability theory and computer science literature are "self-replicating programs", "self-reproducing programs", and "self-copying programs". A quine is a fixed point of an execution environment, when that environment is viewed as a function transforming programs into their outputs. Quines are possible in any Turing-complete programming language, as a direct consequence of Kleene's recursion theorem. For amusement, programmers sometimes attempt to develop the shortest possible quine in any given programming language. The idea of self-reproducing automata came from the dawn of computing, if not before. John von Neumann theorized about them in the s.

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A more general approach we can use is to have some blob of data, and use it in the output twice; once to represent itself, and again to represent the rest of the code. There actually is another really cool way to get the quotes in Perl: you can use q for quoting. Sounds like the blank file was already a Quine! This version while a bit cumbersome solves the quotation marks problem by just explicitly printing the ascii characters. APL has some cute quines. Please Login to comment And no need to stop there: once you have that program, you can print IT. The trick is getting the string just right. It appears to be right on the borderline of cheating. Campus Experiences.

So, first things first:. Roughly speaking, a quine is a self-reproducing program: if you run it, it generates itself. Devising the shortest possible quine in some given programming language is a common hackish amusement.

Python Merge Python key values to list. Lua has a load function that creates a function from a string that can be used in a similar way. The lowercase r is the input data. The two representations of the data are very different to each other. Like Article Like. Contribute to the GeeksforGeeks community and help create better learning resources for all. A good example of this approach is this quine in Assembly. Python Add Logging to Python Libraries. Cheating is not allowed: the command line arguments must not be too long — passing the full text of a program is considered cheating. Now instead of printing the same data string twice verbatim, the second time we transform the escaped quotes back into quotes. Quines, per definition, cannot receive any form of input, including reading a file, which means a quine is considered to be "cheating" if it looks at its own source code. It appears to be right on the borderline of cheating. The quine concept can be extended to multiple levels of recursion, giving rise to " ouroboros programs", or quine-relays. Like most things in Bash, this one uses an interesting quirk.