Question

Python is creating a folder in my directory every time I call this method. The method is in one of my Django applications that requires access to the server’s local area.

def filepath(filename, foldername='', envar='MYAPPDIR'):

    if envar is not None and envar is os.environ:
        dirpath = os.environ[envar]
    else:
        dirpath = '~/myFolder/%s' % foldername    

    expanded = os.path.expanduser(dirpath)
    if not os.path.isdir(expanded):
        if os.path.lexists(expanded):
            raise IOError(errno.EEXIST, "Path is a file, nor a dir", expanded)
        os.makedirs(expanded)

    return os.path.join(expanded, filename)

I’d like to stop it from happening.

Please note: the user can specify if it’s in another directory within the default. Therefore the default folder is myFolder, however if the user wants to use a folder called myOtherFolder within myFolder (therefore ~/myFolder/myOtherFolder/) then they can. This is the kind of functionality I’m trying to implement, hence my using folder='' if no argument is passed to the method(which I think is the problem).

Answer 1

def filepath(filename, foldername=None, envar='MYAPPDIR'):
  default = '~/myFolder'
  if foldername:
    default = os.path.join(default, foldername)
  dirpath = os.path.expanduser(os.environ.get(envar, default))

  try:
    os.makedirs(dirpath)
  except OSError as e:
    if e.errno != errno.EEXIST:
      raise
  return os.path.join(dirpath, filename)

Biggest change removing the “is” typo you had in the first if’s condition (did you mean “in”?).

However, it appears you want envar to override “~/myFolder”, not “~/myFolder/otherSpecifiedByUser”, giving:

def filepath(filename, foldername=None, envar='MYAPPDIR'):
  dirpath = os.path.expanduser(os.environ.get(envar, "~/myFolder"))
  if foldername:
    dirpath = os.path.join(dirpath, foldername)

  try:
    os.makedirs(dirpath)
  except OSError as e:
    if e.errno != errno.EEXIST:
      raise
  return os.path.join(dirpath, filename)

Also, if you’re storing config files, then you can trivially follow the XDG basedir spec, if you’re really using something like “~/.myFolder”:

def filepath(filename, foldername=None, envar='MYAPPDIR'):
  default = os.path.join(os.environ.get("XDG_CONFIG_HOME", "~/.config"), "myFolder")
  dirpath = os.path.expanduser(os.environ.get(envar, default))
  if foldername:
    dirpath = os.path.join(dirpath, foldername)

  try:
    os.makedirs(dirpath)
  except OSError as e:
    if e.errno != errno.EEXIST:
      raise
  return os.path.join(dirpath, filename)