Unladen Swallow was an optimization branch of CPython, the

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of the

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, which incorporated a

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built using

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into CPython's

virtual machine In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve ...

. Like many things regarding Python (and the name "Python" itself), "Unladen Swallow" is a

Monty Python Monty Python, also known as the Pythons, were a British comedy troupe formed in 1969 consisting of Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones and Michael Palin. The group came to prominence for the sketch comedy ser ...

reference, specifically to the joke about the airspeed velocity of unladen

swallow The swallows, martins, and saw-wings, or Hirundinidae are a family of passerine songbirds found around the world on all continents, including occasionally in Antarctica. Highly adapted to aerial feeding, they have a distinctive appearance. The ...

s in ''

Monty Python and the Holy Grail ''Monty Python and the Holy Grail'' is a 1975 British comedy film based on the Arthurian legend, written and performed by the Monty Python comedy group (Graham Chapman, John Cleese, Terry Gilliam, Eric Idle, Terry Jones, and Michael Palin) and ...

''. The project's stated goals were to provide full compatibility with CPython specific code while quintupling its performance, and for the project to eventually be merged into CPython. Although it fell short of all its published goals, some Unladen Swallow code was added into the main Python implementation, such as improvements to the cPickle module. Unladen Swallow was sponsored by

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, and the project owners, Thomas Wouters, Jeffrey Yasskin, and Collin Winter, were Google employees, though most project contributors were not. Unladen Swallow was hosted on

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. In March 2010, a

Python Enhancement Proposal Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically type-checked and garbage-collected. It supports multiple program ...

(PEP) which proposed merging Unladen Swallow into a special py3k-jit branch of Python's official

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was accepted. However, its implementation was made difficult by Unladen being based on Python 2.6, with which

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broke compatibility, and the PEP was subsequently withdrawn. In July 2010, speculation began on whether the project was dead or dying since the 2009 Q4 milestone had not yet been released, and the traffic on Unladen's mailing list had decreased from 500 messages in January 2010 to fewer than 10 in September 2010. It had also been reported that Unladen had lost Google's funding, and in November 2010, Collin announced that "Jeffrey and I have been pulled on to other projects of higher importance to Google". By early 2011, it was clear that the project was stopped.

Release history

* 2009 Q1 * 2009 Q2 * 2009 Q3: reduce memory use, improve speed A 2009 Q4 development branch was created in January 2010, but was not advertised on the website, and its milestone was unmet.

References

{{reflist Python (programming language) implementations Monty Python references

Release history

See also

References