若满足条件，则将数据帧中列中的值更改为另一个值

Question

我有一个csv文件，它的分隔符是逗号，同时值之间用“.”分隔

当原始值为“-”或该值不存在时，我希望将Pandas中数据帧的ISIN列的值更改为“现金”，如下面的示例所示。我如何做到这一点

我复制并粘贴了sample.csv文件，如下所示：

Emittententicker,Name,Anlageklasse,Gewichtung (%),Kurs,Nominale,Marktwert,Nominalwert,Sektor,ISIN,Börse,Standort,Marktwährung
"AAPL","APPLE INC","Aktien","3,63","123,54","1.722.459","212.792.585","212.792.584,86","IT",,"NASDAQ","Vereinigte Staaten","USD"
"MSFT","MICROSOFT CORP","Aktien","3,08","245,71","735.512","180.722.654","180.722.653,52","IT","-","NASDAQ","Vereinigte Staaten","USD"
"AMZN","AMAZON COM INC","Aktien","2,38","3.187,01","43.863","139.791.820","139.791.819,63","Zyklische Konsumgüter ","-","NASDAQ","Vereinigte Staaten","USD"
"GOOG","ALPHABET INC CLASS C","Aktien","1,24","2.404,61","30.223","72.674.528","72.674.528,03","Kommunikation","US02079K1079","NASDAQ","Vereinigte Staaten","USD"