ignore_index

import pandas as pd
from IPython.core.display import display

data={'name':['张三','李四','王五','小明'],'sex':['female','female','male','male'],
      'year':[2001,2001,2003,2004],'city':['北京','上海','广州','北京']}
df1=pd.DataFrame(data,columns=['name','sex','year','city'])

df3=df1.set_index(['sex','city'])
df3=df3.reset_index(['sex'])
print(df3)
data1={'year':2001,'name':'lanlan','sex':'male','city':'北京'}
df4=df3.append(data1,ignore_index=True)
print(df4)

结果：

         sex name  year
city                   
北京    female   张三  2001
上海    female   李四  2001
广州      male   王五  2003
北京      male   小明  2004
      sex    name  year city
0  female      张三  2001  NaN
1  female      李四  2001  NaN
2    male      王五  2003  NaN
3    male      小明  2004  NaN
4    male  lanlan  2001   北京

Process finished with exit code 0

import pandas as pd
from IPython.core.display import display

data={'name':['张三','李四','王五','小明'],'sex':['female','female','male','male'],
      'year':[2001,2001,2003,2004],'city':['北京','上海','广州','北京']}
df1=pd.DataFrame(data,columns=['name','sex','year','city'])
print(df1)
data1={'year':2001,'name':'lanlan','sex':'male','city':'北京'}
df4=df1.append(data1,ignore_index=True)
print(df4)

结果：

  name     sex  year city
0   张三  female  2001   北京
1   李四  female  2001   上海
2   王五    male  2003   广州
3   小明    male  2004   北京
     name     sex  year city
0      张三  female  2001   北京
1      李四  female  2001   上海
2      王五    male  2003   广州
3      小明    male  2004   北京
4  lanlan    male  2001   北京

Process finished with exit code 0