Question

python的新手，我对此深感困惑。我的CSV文件包含以下内容：

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.function.Consumer;
import java.lang.Integer;

public class ForEachExample {

    public static void main(String[] args) {

        //creating sample Collection
        List<Integer> myList = new ArrayList<Integer>();
        for(int i=0; i<10; i++) myList.add(i);

        //traversing using Iterator
        Iterator<Integer> it = myList.iterator();
        while(it.hasNext()){
            Integer i = it.next();
            System.out.println("Iterator Value::"+i);
        }

        //traversing through forEach method of Iterable with anonymous class
        myList.forEach(new Consumer<Integer>() {

            public void accept(Integer t) {
                System.out.println("forEach anonymous class Value::"+t);
            }

        });

        //traversing with Consumer interface implementation
        MyConsumer action = new MyConsumer();
        myList.forEach(action);

    }

}

//Consumer implementation that can be reused
**class MyConsumer implements Consumer<Integer>{
    public void accept(Integer t) {
        System.out.println("Consumer impl Value::"+t);
    }
}**

现在，我想将Gender值转换为二进制值，以便文件看起来像这样：

Sr,Gender
1,Male
2,Male
3,Female

因此，我将CSV文件导入为Sr,Gender 1,1 2,1 3,0并运行了以下代码：

data

但是我收到了错误data["Gender_new"]=1 data["Gender_new"][data["Gender"]=="Male"]=0 data["Gender_new"]=1=data["Gender_new"].astype(float)

我在做什么错了，我该怎么做？

谢谢

Answer 1

尝试一下：

import pandas as pd

file = open("your.csv", "r")

data = pd.read_csv(file, sep = ",")

gender = {'male': 1,'female': 0}

data.Gender = [gender[item] for item in data.Gender]
print(data)

或

data.Gender[data.Gender == 'male'] = 1
data.Gender[data.Gender == 'female'] = 0
print(data)

Answer 2

您可以在加载文件时进行转换：

d = pandas.read_csv('yourfile.csv', converters={'Gender': lambda x: int(x == 'Male')})

converters参数采用一个字典，其键是列名（或索引），而值是为每个项目调用的函数。该函数必须返回转换后的值。

另一种方法是在拥有数据框后将其转换，如@DJK在其注释中指出的那样：

data['Gender'] = (data['Gender'] == 'Male').astype(int)

如何将列中的值更改为二进制？

2 个答案: