合并后数据框中的列从整数转换为浮点数

Question

find_originatorId = function(current_row, df){
    if(current_row[["prevId"]] == ""){
        current_row[["id"]]
    } else {
        parent_row = df[df$id == current_row[["prevId"]],]
        find_originatorId(parent_row, df)
    }
}

df$originatorId = apply(df, 1, find_originatorId, df)

多列转换为浮点数。 我试图转换回int。

>>> df=pd.merge(df1,df2 ,on=['id'],how='left')

>>> df['num']=df['num'].astype(int) ValueError: Cannot convert non-finite values (NA or inf) to integer 具有2,000多行。如何更改回int