python - 为什么意外缩进？

Question

为什么会这样？

def LoadPackageList():
    try:
        #Attempts to load package list... Adds each neccessary attribute into array
        print("Loading Package List... please wait")
        packages = []
        packagelisturl = os.getcwd() + "packages.list"
        dom = minidom.parse(urllib.urlopen(packagelisturl))
        try:
            for eachattributeofpkglist in dom.GetElementsByTagNameNS(packagelist, 'packages'):
                packages.append({
                    'title': node.getAttribute('title'),
                    'shortname': node.getAttribute('shortname'),
                    'dlurl': node.getAttributes('dlurl'),
                    'description': node.getAttributes('description'),
                    'tags': node.getAttributes('tags'),
                    'infopage': node.getAttributes('infopage'),
                    'quality': node.getAttributes('quality'),
                    'id': node.getAttributes('id')
            })

        except LoadPackageListFailed:
            print("Loading Package List failed... try again soon or manually update this release!")
            Write2ErrorLog(LoadPackageListFailed)
#Indent Here Fails            
def Usage():
#prints usage and closes
    print ("Invalid Argument Specified, please retry using the format stated below\n")
    print ("*** Simtho Usage Parameters ***\n")
    print ("-i Installs Local App, include full path")
    print ("-u Uninstalls Installed App,include ID or Name")
    print ("-l Lists all installed Apps and their ID")
    print ("-a Lists All Apps in Repository")
    print ("-s Downloads and Installs App from repository, enter the title or id number")
    print ("-w Downloads and Installs Single App from a full link")
    print ("-r Removes All Packages installed\n")
    print ("*** End of Simtho Usage ***")
    os._exit(1)
    return;

Answer 1

尝试通过 python -t 运行它，看看其中某处是否混合了制表符和空格。

作为旁注:使用 optparse处理命令行参数。它将使您的生活更轻松，并产生一个漂亮的一致界面。