help with counter

[andy]

On Monday 06 Jan 2003 8:20 pm, Bill Carter wrote:
> I must have been looking at this problem for to  long, but I need some
> help because I am stuck.
>
> I have a series of files on disk   file.01.txt, file.02.txt ...
> what I am trying to do is rename all the files a new name but also not
> renaming a few files but maintaining the number sequence
>
> for example
>
> #sample command line
> pyrename.py file.01.txt file.400.txt  3 newfile.01.txt
>
> # breakdown
> script name / filename of first file / last filename / drop every 3rd
> file / new filename and start number
>
>
> should produce
>
> file.01.txt     	newfile.01.txt
> file.02.txt	newfile.02.txt
> file.03.txt
> file.04.txt	newfile.03.txt
> file.05.txt	newfile.04.txt
> file.06.txt	newfile.05.txt
> file.07.txt	newfile.06.txt
> file.08.txt
> file.09.txt	newfile.07.txt
> file.10.txt ...	newfile.08.txt...
>
> the filename changes the amount changes and the file to be dropped
> changes.
>
> For some reason I can't put my head around this problem.  Any help
> would be appreciated.
>
> BC

Bill some thoughts:

    change params to:

start-no finish-no drop-no old-format new-format  

use the % operator to mangle the output name

ie:

pyrename.py 1 400 3 file.%i.txt file.%i/txt

#pyrename
import os,string

# get params etc...
start_no=1
finish_no=10
drop_no=3
old_fmt="file.%i.txt"
new_fmt="new.fmt.%i.file"
dirname="/home/andy/pyrename.test"

########### processing starts here #########

# figure out where number is in name
specparts=string.split(old_fmt,".") # get the string bits
numpart=0
for part in specparts:
    if part[0]=="%": # this is it
        break
    else:
        numpart+=1

files=os.listdir(dirname) # you supply dirname

# drop unwanted filenames, ie, before start_no, after finish_no and 
# modulus drop_no
oldlist=files[:] # new copy of files list
for file in oldlist:
    fileparts=string.split(file,".")
    num=int(fileparts[numpart])
    # obliterate number part in fileparts to make comparison easy
    fileparts[numpart]=specparts[numpart]
    # remove if unwanted
    if fileparts<>specparts: # this file does not match spec
        files.remove(file)
    elif num<start_no or num>finish_no or (num % drop_no) == 0:
        files.remove(file)


# list now only has files we want in it
count=start_no
for file in files:
    new_name=new_fmt % count
    os.rename(dirname+"/"+file,new_name) # non portable path splice
    count+=1


############### end

test:
bash-2.05b$ cd pyrename.test/
bash-2.05b$ touch file.1.txt
bash-2.05b$ touch file.002.txt
bash-2.05b$ touch untouched.333.txt
bash-2.05b$ touch file.003.txt
bash-2.05b$ touch file.004.txt
bash-2.05b$ touch file.005.txt
bash-2.05b$ touch file.006.txt
bash-2.05b$ touch file.007.txt
bash-2.05b$ touch file.008.txt
bash-2.05b$ touch file.009.txt
bash-2.05b$ touch file.10.txt
bash-2.05b$ ls
file.002.txt  file.005.txt  file.008.txt  file.1.txt
file.003.txt  file.006.txt  file.009.txt  untouched.333.txt
file.004.txt  file.007.txt  file.10.txt
bash-2.05b$ python ../pyrename.py
['file.1.txt', 'file.002.txt', 'file.004.txt', 'file.005.txt', 'file.007.txt', 
'file.008.txt', 'file.10.txt']
bash-2.05b$ ls
file.003.txt  new.fmt.1.file  new.fmt.4.file  new.fmt.7.file
file.006.txt  new.fmt.2.file  new.fmt.5.file  untouched.333.txt
file.009.txt  new.fmt.3.file  new.fmt.6.file
bash-2.05b$