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    Non-Programmer’s Tutorial for Python

    12th August 2007

    Non-Programmer’s Tutorial for Python


    Posted in Links, Programming, Python | No Comments »

    Python: iterate (and read) all files in a directory (folder)

    12th August 2007

    To iterate through all the files within the specified directory (folder), with ability to use wildcards (*, ?, and [ ]-style ranges), use the following code snippet:
    Read the rest of this entry »


    Posted in Programming, Python | 39 Comments »

    Why Zope 3 is just great

    15th March 2007

    Recently I learned about Zope, which is an “open source web application server”, primarily written in Python.

    Then Django and Turbogears were seen as web-development frameworks akin to Zope. Search revealed an interesting anti-Zope rant at Zope vs Django. Reading until the end, and then following the comments, I came across the comment by Holger Froebe, which is a huge one (probably the longest comment I had ever seen), and represents a detailed explanation with examples of the reasons to use Zope 3. I found that comment to be a really good-written one, so if you are deciding on whether you should use Zope 3 or not, then read the comment here (scroll down or just search for “Holger Froebe”).

    For convenience and in order to preserve this worhty piece of work from vanishing, below is the 99%-exact copy-paste of that comment.
    Read the rest of this entry »


    Posted in CMS, Programming, Python, Software, Web | 1 Comment »

    Simple substring counting script in Python

    21st June 2006

    Approximately a month ago I endeavoured to use Python as my main shell-scripting language. At that moment, I was already aware of multiple benefits you get when you use Python for scripting:

    • source-level cross-platform scripting: your script will run anywhere, where Python compiles; expanding this statement – your script will run anywhere, where there is a C compiler (needed to build Python itself)
    • high-level language: you can iterate all the lines in a text file with as little as one ‘for’-statement, for example (see the actual example below)
    • simple/minimalist syntax: no curly braces around blocks of statements, no semicolons after each and every line of code, etc. Python at a glance looks much more understandable, than, for example, Perl.
    • the power of C in a language-interpreting system
    • it is interpreted! This gives easyness of debugging: modify, execute, see the trouble – with no compile/link stages
    • and, despite being interpreted, it is fast!

    For the comparison (in speed, memory use, program size) with other computer programming languages, please see the “Computer Language Shootout Benchmarks”. Here I provide the link only to the comparison of Python with Perl and comparison of Python with PHP (which can also be used as shell-scripting language, albeit after some tinkering with settings and stuff)

    Below is an example of the 2-minute script in Python, which counts the number of occurrences of some string in a file.

    1. """Read FILE and count number of occurences of SUBSTR."""
    2. version = 0.01
    4. import sys
    6. def main():
    7.   from optparse import OptionParser
    8.   opts = OptionParser(usage="%prog [options] FILE SUBSTR",
    9.     version="%prog " + str(version),
    10.     description="Read FILE and count number of occurences of SUBSTR.")
    11.   opts.set_defaults(verbose=False,flush=False)
    12.   opts.add_option("-v", "--verbose", action="store_true", dest="verbose", help="Print every line containing substr [default: %default]")
    13.   opts.add_option("-f", "--flush", action="store_true", dest="flush", help="When verbose, flush every line [default: %default]")
    14.   (options, args) = opts.parse_args()
    16.   if len(args) != 2:
    17.     print "Two arguments required for correct processing"
    18.     opts.print_help()
    19.     sys.exit(2)
    21.   infile = args[0]
    22.   substr = args[1]
    23.   lines_count = 0
    24.   substr_count = 0
    25.   lines_substr_count = 0
    26.   if options.verbose and not options.flush:
    27.     msg = ""
    29.   f = open(infile, 'r')
    30.   for line in f:
    31.     lines_count += 1
    32.     found = line.count(substr)
    33.     substr_count += found
    34.     if found > 0:
    35.       lines_substr_count += 1
    36.       if options.verbose and not options.flush:
    37.         msg += str(found) + ": " + line
    38.       elif options.verbose and options.flush:
    39.         print (str(found) + ": " + line).replace("n","")
    41.   f.close()
    43.   if options.verbose and not options.flush:
    44.     print msg
    45.   print "Lines read from file: ", str(lines_count)
    46.   print "Lines with substring found: ", str(lines_substr_count)
    47.   print "Total substrings detected: ", str(substr_count)
    49.   return
    51. if __name__ == "__main__":  main()

    Posted in Programming, Python | 4 Comments »