Yesterday I had a dream. About Python… I dreamed of some Python one-liners…

Many ppl have seen the awk1line and sed1line. And yet many ppl think Python is bloated, indent-hog. But I just want to prove that Python is not that bad at this aspect… Bloated but clear in thoughts! I'll follow awk1line as requirements and try Python one-liner implemention. I'm not very good at programming though so I'll do this progressively…

I'll put a one-page version in my wiki for others to edit, if exists…

 # double space a file 
 python -c 'import sys; print "\n".join(line for line in sys.stdin)'

 # double space a file which already has blank lines in it. Output file
 # should contain no more than one blank line between lines of text.
 python -c 'import sys; print "\n".join(line for line in sys.stdin if not len(line) == 0 )'

 # triple space a file
 python -c 'import sys; print "\n\n".join(line for line in sys.stdin)'

 # precede each line by its line number FOR THAT FILE (left alignment).
 # Using a tab (\t) instead of space will preserve margins.
 python -c 'import sys; print "".join("%d\t%s"%(n + 1, line) for (n, line) in enumerate(sys.stdin))'

 # precede each line by its line number FOR ALL FILES TOGETHER, with tab.
 python -c 'import sys,glob; map(lambda file: sys.stdout.write("".join("%d\t%s"%(n + 1, line) for(n, line) in enumerate(open(file)))), glob.glob("*"));'

 # number each line of a file (number on left, right-aligned)
 # Double the percent signs if typing from the DOS command prompt.
 python -c 'import sys; print "".join("%5d %s"%(n + 1, line) for (n, line) in enumerate(sys.stdin))'

 # number each line of file, but only print numbers if line is not blank
 # Remember caveats about Unix treatment of \r (mentioned above)
 python -c 'import sys; print "".join("%5d %s"%(n + 1, line) for (n, line) in enumerate(sys.stdin) if len(line)>0)'

 # count lines (emulates "wc -l")
 python -c 'import sys; print sum(1 for line in sys.stdin)'

To be continued…