testwnet.py 文件源码

def findUnusedDriveLetter():
    existing = [x[0].lower() for x in win32api.GetLogicalDriveStrings().split('\0') if x]
    handle = win32wnet.WNetOpenEnum(RESOURCE_REMEMBERED,RESOURCETYPE_DISK,0,None)
    try:
        while 1:
            items = win32wnet.WNetEnumResource(handle, 0)
            if len(items)==0:
                break
            xtra = [i.lpLocalName[0].lower() for i in items if i.lpLocalName]
            existing.extend(xtra)
    finally:
        handle.Close()
    for maybe in 'defghijklmnopqrstuvwxyz':
        if maybe not in existing:
            return maybe
    raise RuntimeError("All drive mappings are taken?")