python to codeand it limits python programs to an implicit statically typed constraint that is typical of most programs but is technically not normal pythonso we won' go into further detail here initial resultsthoughshow that it has the potential to outperform both standard python and psyco-like extensions in terms of execution speed search the web for details on the project' current status psycothe original just-in-time compiler the psyco system is not another python implementationbut rather component that extends the byte code execution model to make programs run faster todaypsyco is something of an ex-projectit is still available for separate downloadbut has fallen out of date with python' evolutionand is no longer actively maintained insteadits ideas have been incorporated into the more complete pypy system described earlier stillthe ongoing importance of the ideas psyco explored makes them worth quick look in terms of figure - psyco is an enhancement to the pvm that collects and uses type information while the program runs to translate portions of the program' byte code all the way down to true binary machine code for faster execution psyco accomplishes this translation without requiring changes to the code or separate compilation step during development roughlywhile your program runspsyco collects information about the kinds of objects being passed aroundthat information can be used to generate highly efficient machine code tailored for those object types once generatedthe machine code then replaces the corresponding part of the original byte code to speed your program' overall execution the result is that with psycoyour program becomes quicker over time as it runs in ideal casessome python code may become as fast as compiled code under psyco because this translation from byte code happens at program runtimepsyco is known as just-in-time compiler psyco is different from the jit compilers some readers may have seen for the java languagethough reallypsyco is specializing jit compiler-it generates machine code tailored to the data types that your program actually uses for exampleif part of your program uses different data types at different timespsyco may generate different version of machine code to support each different type combination psyco was shown to speed some python code dramatically according to its web pagepsyco provides " to speed-upstypically xwith an unmodified python interpreter and unmodified source codejust dynamically loadable extension module of equal significancethe largest speedups are realized for algorithmic code written in pure python--exactly the sort of code you might normally migrate to to optimize for more on psycosearch the web or see its successor--the pypy project described previously how python runs programs