python - 在此代码中，如何在使用 python 找到或未找到字符串后停止

Question

import win32com.client
objSWbemServices = win32com.client.Dispatch(
    "WbemScripting.SWbemLocator").ConnectServer(".","root\cimv2")
for item in objSWbemServices.ExecQuery(
        "SELECT * FROM Win32_PnPEntity "):
    found=False
    for name in ('Caption','Capabilities '):
        a = getattr(item, name, None)
        if a is not None:
            b=('%s,' %a)
            if "Item" in b:
                print "found"
                found = True

            else:
                print "Not found"
                break

我只想一次显示“找到”否则“未找到”

Answer 1

另一种方法是使用一个函数并在你有 print 的地方替换 return。您可以利用 python 中的函数在返回时停止执行的事实。

def finder():
    objSWbemServices = win32com.client.Dispatch(
        "WbemScripting.SWbemLocator").ConnectServer(".","root\cimv2")
    for item in objSWbemServices.ExecQuery(
        "SELECT * FROM Win32_PnPEntity "):
        for name in ('Caption','Capabilities '):
            a = getattr(item, name, None)
            if a is not None:
                b=('%s,' %a)
                if "Item" in b:
                    return True # or return "Found" if you prefer
                else:
                    return False # or return "Not Found" if you prefer

found = finder()
print found
# or
print finder()

Answer 2

您必须在“if”案例之后添加“break”，如下所示：

for name in ('Caption','Capabilities '):
    a = getattr(item, name, None)
    if a is not None:
        b=('%s,' %a)
        if "Item" in b:
            print "found"
            found = True

            #added here
            break

        else:
            print "Not found"
            break

这将打破“（'Caption'，'Capabilities'）”的迭代

Answer 3

上移break一级缩进：

for name in ('Caption','Capabilities '):
    a = getattr(item, name, None)
    if a is not None:
        b=('%s,' %a)
        if "Item" in b:
            print "found"
            found = True
        else:
            print "Not found"

        break

Answer 4

展示？你的意思是执行，我想。只需将 break 放在 else 语句之外（在里面 - 如果 a 不是 None -）。这样，如果 a 不是 none，则只要“Item”在 b 中，循环就会停止。

for name in ('Caption','Capabilities '):
    a = getattr(item, name, None)
    if a is not None:
        b=('%s,' %a)
        if "Item" in b:
            print "found"
            found = True

        else:
            print "Not found"
        break

编辑：见warwaruk anser