我正在使用PHPlibraryforOAuth2.0v20在draft20中，有一个mentionoftheuseofstatetopreventCSRF到目前为止，我自己的实现此PHP库的Web应用程序允许执行以下操作:3leggedauthenticationusingAuthorizationCodeRequest2leggedauthenticationusingResourceOwnerCredentialsGrantaRequestthatrefreshesanaccesstoken我是否需要在上述所有3种情况下都使用状态？如果是这样，“状态”的一个很好的例子是什么？什么是

我正在使用PHPlibraryforOAuth2.0v20在draft20中，有一个mentionoftheuseofstatetopreventCSRF到目前为止，我自己的实现此PHP库的Web应用程序允许执行以下操作:3leggedauthenticationusingAuthorizationCodeRequest2leggedauthenticationusingResourceOwnerCredentialsGrantaRequestthatrefreshesanaccesstoken我是否需要在上述所有3种情况下都使用状态？如果是这样，“状态”的一个很好的例子是什么？什么是

我从这样的输入数据开始df1=pandas.DataFrame({"Name":["Alice","Bob","Mallory","Mallory","Bob","Mallory"],"City":["Seattle","Seattle","Portland","Seattle","Seattle","Portland"]})打印出来的时候是这样的:CityName0SeattleAlice1SeattleBob2PortlandMallory3SeattleMallory4SeattleBob5PortlandMallory分组很简单:g1=df1.groupby(["Name","

我从这样的输入数据开始df1=pandas.DataFrame({"Name":["Alice","Bob","Mallory","Mallory","Bob","Mallory"],"City":["Seattle","Seattle","Portland","Seattle","Seattle","Portland"]})打印出来的时候是这样的:CityName0SeattleAlice1SeattleBob2PortlandMallory3SeattleMallory4SeattleBob5PortlandMallory分组很简单:g1=df1.groupby(["Name","