Guido van Rossum Interviewed

Qa1 writes "Guido von Rossum, creator of Python, was recently interviewed by the folks at O'Reilly Network. In this interview he discusses his view of the future of Python and the Open Source community and programming languages in general. Some more personal stuff is also mentioned, like his recent job change (including the Slashdot story about it) and a little about how he manages to fit developing Python into his busy schedule."

Comments

Re:Is Python still lacking a macro system?

[Ian Bicking]

No, Python doesn't and won't have a macro system. The Lisp features like lambda and map are kind of in disrepute, at least from Guido's perspective -- see comp.lang.python for many opinions on the matter. Since Guido is Benevolent Dictator For Life, his opinion holds a great deal of sway. (BTW, map has been replaced with list comprehension, taken from Haskell, so it's not like functional programming as a whole is being rejected)

Macros would indeed be more difficult to implement in Python, because data and code are not as interchangable as in Lisp (e.g., (car 1 2) being code, '(car 1 2) being data). Macro-like manipulations of Python code would be rather difficult. But there has been discussions about ways of achieving the same flexibility without quite so much generality.

In a related example, some people feel that code blocks, ala Ruby or Smalltalk, are the right way to do control structures. Indeed they are very general. Python instead has developed notions of iteration, generation, and the use of first-class functions, and together they are all quite general as well -- you can do what you need to do. While more eclectic than anonymous functions/lambdas/closures, they are arguably more transparent -- you don't know what a function might do with a code block, and it can greatly effect surrounding code.

So it is with macros -- they are extremely general, and can do unexpected and magic things, (which is not in fitting with core Python principals). As Python grows alternatives, more things need to be built into the languages, but the result is a set of predictable and well-known idioms. Python is a full language, not the basis for other languages, as Lisp can become.

As far as performance, there are a number of things like Psyco, Pyrex, Numeric, and Weave/SciPy, which can handle performance problems (noting that in most application performance is not a problem). The result is again somewhat eclectic, but pragmatic. There's a wide variety of ways to optimize a Python program, many of which are just normal programming optimization (caching, making a process persistent, lazy loading, etc), as well as Python modules written in C or other compiled languages (potentially aided by things like SWIG, Pyrex, or ctypes)