file_name_fixer.py

[Fredrik Lundh]

Steven D'Aprano wrote:

> You should consider factoring out some repeated code
> into functions. E.g.:
>
> # warning: untested!!!
> def replace_all(s, old, new):
>      """Replaces all instances of substring old with
>      substring new."""
>      if old == new:
>          # make no changes
>          return s
>      elif old in new:
>           raise ValueError("old substring can't be "
>               "part of the replacement substring.")
>      while old in s:
>          s = s.replace(old, new)
>      return s
>
> Now you can call it in your loop:
>
> > for path, subdirs, files in os.walk(dir, topdown=True):
> >     oldname = path
> >     newname = oldname.translate(chars)
> >     newname = string.lower(newname)
>
> >     while string.count(newname, "__") > 0:
> >         newname = string.replace(newname,"__","_")
> >     while string.count(newname, "..") > 0:
> >         newname = string.replace(newname,"..",".")
>
> becomes:
>
> newname = replace_all(newname, "__", "_")
> newname = replace_all(newname, "..", ".")

or you can use a more well-suited function:

    # replace runs of _ and . with a single character
    newname = re.sub("_+", "_", newname)
    newname = re.sub("\.+", ".", newname)

or, slightly more obscure:

    newname = re.sub("([_.])\\1+", "\\1", newname)

</F>