如何从mongodb map reduce python处理不区分大小写的代码？

Question

这是我的代码段，用于检查多余的questionText，并将其从集合中删除。现在我要检查不区分大小写 外汇：CHINA，中国检查是否有重复，从中删除一个

我的代码：

myclient = pymongo.MongoClient("mongodb://localhost:3000/")
print("Connection Successful")
mydb = myclient["demo"]
mycol2 = mydb["questions"]

map = Code("function(){ if(this.questionText){emit(this.questionText,1);}}")
reduce = Code("function(key,values) {"
    "return Array.sum(values);"
"}")

res = mycol2.map_reduce(map,reduce,"my_results");

response = []
for doc in res.find():
    if(doc['value'] > 1):
        count = int(doc['value']) - 1
        docs = mycol2.find({"questionText":doc['_id']},{'_id':1}).limit(count)
        for i in docs:
            response.append(i['_id'])
            #mycol2.remove({"_id": {"$in": response}})
            print(response)