如何在另一列上创建一个基于时间的约束的pandas列？

Question

我有一个如下所示的数据框，只有2 category A。每个名称可以与每行中的任何一个相关联。当名称再次出现时，我需要其他2列，表示该名称的最后5次交易中该名称的category B和"-1"的计数。如果之前的事务少于5个，则输出应为Document Number Date Due Name Category 21175370 9/20/17 Max A 20762835 8/20/17 Max A 21134931 8/25/17 Emily B 20784776 8/19/17 John A 20874477 8/4/17 Doe B 20874568 8/4/17 Doe B 20874575 8/4/17 Doe B 19784032 5/9/17 Doe B 19980723 5/25/17 Doe B 20833755 9/16/17 Doe A 。所以，我通过对名称进行排序然后在Date Due上对名称进行了数据处理，但不确定如何继续进行。

Document Number   Date Due  Name    Category  Category_A_Count  Category_B_Count
    21175370      9/20/17   Max        A              -1              -1
    20762835      8/20/17   Max        A              -1              -1
    21134931      8/25/17   Emily      B              -1              -1 
    20784776      8/19/17   Doe        A              -1              -1
    20874477      8/4/17    Doe        B              -1              -1
    20874568      8/4/17    Doe        B              -1              -1
    20874575      8/4/17    Doe        B              -1              -1
    19784032      5/9/17    Doe        B              -1              -1
    19980723      5/25/17   Doe        B               1              4
    20833755      9/16/17   Doe        A               0              5

输出如下：

vendorList = list(vendorLast5["Name"])
cat = list(vendorLast5["Category"])
print type(vendorList)
catA = [-1, -1, -1, -1]
catB = [-1, -1, -1, -1]
for i in range(0, len(vendorList)):
    if(i > 4):
        countA = 0
        countB = 0
        for j in range(i-5, i):
            if(vendorList[j] != vendorList[i]):
                countA = -1
                countB = -1
                break
            if(cat[j] == "A"):
                countA = countA+1
            else:
                countB=countB+1
        catA.append(countA)
        catB.append(countB)

我已经通过将pandas数据框更改为列表来尝试了一些东西，这可以完成工作，但我怎么能在熊猫中做到这一点？ ：

class Users: Object {
    dynamic var phoneNumber:String = ""
    dynamic var messageSenderName:String = ""
    let userMessages = List<Messages>()

    override static func primaryKey() -> String? {
        return "phoneNumber"
    }
    // convenience init() here
}

class Messages: Object{
    dynamic var id = UUID().uuidString
    dynamic var phoneNumber:String = ""
    dynamic var messageSenderName:String = ""
    dynamic var messageBody:String = ""
    dynamic var message_id:String = ""
    dynamic var messageTime:String = ""

    override static func primaryKey() -> String? {
        return "id"
    }
    // convenience init here
}