New blurb, derived from my Handbook of Object Technology abstract.
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Misc/BLURB
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Misc/BLURB
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What is Python?
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---------------
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What is Python? Executive Summary
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----------------------------------
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Python is an interpreted, interactive, object-oriented programming
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language. It incorporates modules, exceptions, dynamic typing, very
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high level dynamic data types, and classes. Python combines
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remarkable power with very clear syntax. It has interfaces to many
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system calls and libraries, as well as to various window systems, and
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is extensible in C or C++. It is also usable as an extension language
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for applications that need a programmable interface. Finally, Python
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is portable: it runs on many brands of UNIX, on the Mac, and on
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MS-DOS.
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Python is an interpreted, object-oriented, high-level programming
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language with dynamic semantics. Its high-level built in data
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structures, combined with dynamic typing and dynamic binding, make it
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very attractive for Rapid Application Development, as well as for use
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as a scripting or glue language to connect existing components
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together. Python's simple, easy to learn syntax emphasizes
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readability and therefore reduces the cost of program maintenance.
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Python supports modules and packages, which encourages program
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modularity and code reuse. The Python interpreter and the extensive
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standard library are available in source or binary form without charge
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for all major platforms, and can be freely distributed.
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As a short example of what Python looks like, here's a script to
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print prime numbers (not blazingly fast, but readable!). When this
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file is made executable, it is callable directly from the UNIX shell
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(if your system supports #! in scripts and the python interpreter is
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installed at the indicated place).
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#!/usr/local/bin/python
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# Print prime numbers in a given range
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def main():
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import sys
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min, max = 2, 0x7fffffff
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if sys.argv[1:]:
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min = int(eval(sys.argv[1]))
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if sys.argv[2:]:
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max = int(eval(sys.argv[2]))
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primes(min, max)
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def primes(min, max):
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if 2 >= min: print 2
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primes = [2]
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i = 3
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while i <= max:
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for p in primes:
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if i%p == 0 or p*p > i: break
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if i%p <> 0:
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primes.append(i)
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if i >= min: print i
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i = i+2
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main()
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Often, programmers fall in love with Python because of the increased
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productivity it provides. Since there is no compilation step, the
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edit-test-debug cycle is incredibly fast. Debugging Python programs is
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easy: a bug or bad input will never cause a segmentation
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fault. Instead, when the interpreter discovers an error, it raises an
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exception. When the program doesn't catch the exception, the
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interpreter prints a stack trace. A source level debugger allows
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inspection of local and global variables, evaluation of arbitrary
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expressions, setting breakpoints, stepping through the code a line at
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a time, and so on. The debugger is written in Python itself,
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testifying to Python's introspective power. On the other hand, often
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the quickest way to debug a program is to add a few print statements
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to the source: the fast edit-test-debug cycle makes this simple
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approach very effective.
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