"""Convert a NT pathname to a file URL and vice versa."""

def url2pathname(url):

    """OS-specific conversion from a relative URL of the 'file' scheme

    to a file system path; not recommended for general use."""

    # e.g.

    # ///C|/foo/bar/spam.foo

    # becomes

    # C:\foo\bar\spam.foo

    import string, urllib

    # Windows itself uses ":" even in URLs.

    url = url.replace(':', '|')

    if not '|' in url:

        # No drive specifier, just convert slashes

        if url[:4] == '////':

            # path is something like ////host/path/on/remote/host

            # convert this to \\host\path\on\remote\host

            # (notice halving of slashes at the start of the path)

            url = url[2:]

        components = url.split('/')

        # make sure not to convert quoted slashes :-)

        return urllib.unquote('\\'.join(components))

    comp = url.split('|')

    if len(comp) != 2 or comp[0][-1] not in string.ascii_letters:

        error = 'Bad URL: ' + url

        raise IOError, error

    drive = comp[0][-1].upper()

    components = comp[1].split('/')

    path = drive + ':'

    for  comp in components:

        if comp:

            path = path + '\\' + urllib.unquote(comp)

    return path

def pathname2url(p):

    """OS-specific conversion from a file system path to a relative URL

    of the 'file' scheme; not recommended for general use."""

    # e.g.

    # C:\foo\bar\spam.foo

    # becomes

    # ///C|/foo/bar/spam.foo

    import urllib

    if not ':' in p:

        # No drive specifier, just convert slashes and quote the name

        if p[:2] == '\\\\':

        # path is something like \\host\path\on\remote\host

        # convert this to ////host/path/on/remote/host

        # (notice doubling of slashes at the start of the path)

            p = '\\\\' + p

        components = p.split('\\')

        return urllib.quote('/'.join(components))

    comp = p.split(':')

    if len(comp) != 2 or len(comp[0]) > 1:

        error = 'Bad path: ' + p

        raise IOError, error

    drive = urllib.quote(comp[0].upper())

    components = comp[1].split('\\')

    path = '///' + drive + '|'

    for comp in components:

        if comp:

            path = path + '/' + urllib.quote(comp)

    return path