Question

我有一个数据框df1，其中包含一些文本和数字作为列。我用数据创建了新行，并使用pandas附加到df1，如下所示。结果df的id正在改变。有没有办法主df1的id没有改变，并附加到现有的df，而不改变df的id？

我的代码是：

import cStringIO as io
import pandas as pd

def test():
    text_data = """bcd  11  
    abc  12  
    def  13
    ghi  14"""

    df = pd.read_csv(io.StringIO(text_data), header=None, sep="\s+", names=["txt", "num"])
    df2 = pd.DataFrame([["pqr", 1]], columns=["txt", "num"])
    print "id is =",id(df), "\n" ,df
    df = pd.concat([df, df2])
    print "id is =", id(df), "\n", df

if __name__ == '__main__':
    test()

Answer 1

如果仅追加一行并使用setting with enlargement，则可以使用concat或append获取新的DataFrame对象（不同id s）：

from pandas.compat import StringIO

def test():
    text_data = """bcd  11  
    abc  12  
    def  13
    ghi  14"""

    df = pd.read_csv(StringIO(text_data), header=None, sep="\s+", names=["txt", "num"])
    df2 = pd.DataFrame([["pqr", 1]], columns=["txt", "num"])
    print ("id is =",id(df), "\n" ,df)
    df.loc[len(df.index)] = df2.iloc[0]
    print ("id is =", id(df), "\n", df)

test()

id is = 243587168 
    txt  num
0  bcd   11
1  abc   12
2  def   13
3  ghi   14
id is = 243587168 
    txt  num
0  bcd   11
1  abc   12
2  def   13
3  ghi   14
4  pqr    1

在附加到现有df的pandas中，没有更改df的id？

1 个答案: