连接的一个有用的快捷方式是在Series和DataFrame实例的append方法。这些方法实际上早于concat()方法。 它们沿axis=0连接
#encoding:utf8
import pandas as pd
one = pd.DataFrame({
'Name': ['Alex', 'Amy', 'Allen', 'Alice', 'Ayoung'],
'subject_id':['sub1','sub2','sub4','sub6','sub5'],
'Marks_scored':[98,90,87,69,78]},
index=[1,2,3,4,5])
two = pd.DataFrame({
'Name': ['Billy', 'Brian', 'Bran', 'Bryce', 'Betty'],
'subject_id':['sub2','sub4','sub3','sub6','sub5'],
'Marks_scored':[89,80,79,97,88]},
index=[1,2,3,4,5])
print("one:")
print(one)
print("two:")
print(two)
rs = pd.concat([one,two])
print("rs = pd.concat([one,two])")
print(rs)
print("rs = pd.concat([one,two],keys=['x','y'])")
rs = pd.concat([one,two],keys=['x','y'])
print(rs)
print("结果的索引是重复的; 每个索引重复。如果想要生成的对象必须遵循自己的索引，请将ignore_index设置为True:")
print("rs = pd.concat([one,two],keys=['x','y'],ignore_index=True)")
rs = pd.concat([one,two],keys=['x','y'],ignore_index=True)
print(rs)
print("观察，索引完全改变，键也被覆盖。如果需要沿axis=1添加两个对象，则会添加新列:")
rs = pd.concat([one,two],axis=1)
print(rs)
print("rs = one.append(two):")
rs = one.append(two)
print(rs)
print("append()函数也可以带多个对象:")
rs = one.append([two,one,two])
print(rs) D:\Download\python3\python3.exe D:/Download/pycharmworkspace/s.py
one:
Marks_scored Name subject_id
1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
two:
Marks_scored Name subject_id
1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5
rs = pd.concat([one,two])
Marks_scored Name subject_id
1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5
rs = pd.concat([one,two],keys=['x','y'])
Marks_scored Name subject_id
x 1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
y 1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5
结果的索引是重复的; 每个索引重复。如果想要生成的对象必须遵循自己的索引，请将ignore_index设置为True:
rs = pd.concat([one,two],keys=['x','y'],ignore_index=True)
Marks_scored Name subject_id
0 98 Alex sub1
1 90 Amy sub2
2 87 Allen sub4
3 69 Alice sub6
4 78 Ayoung sub5
5 89 Billy sub2
6 80 Brian sub4
7 79 Bran sub3
8 97 Bryce sub6
9 88 Betty sub5
观察，索引完全改变，键也被覆盖。如果需要沿axis=1添加两个对象，则会添加新列:
Marks_scored Name subject_id Marks_scored Name subject_id
1 98 Alex sub1 89 Billy sub2
2 90 Amy sub2 80 Brian sub4
3 87 Allen sub4 79 Bran sub3
4 69 Alice sub6 97 Bryce sub6
5 78 Ayoung sub5 88 Betty sub5
rs = one.append(two):
Marks_scored Name subject_id
1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5
append()函数也可以带多个对象:
Marks_scored Name subject_id
1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5
1 98 Alex sub1
2 90 Amy sub2
3 87 Allen sub4
4 69 Alice sub6
5 78 Ayoung sub5
1 89 Billy sub2
2 80 Brian sub4
3 79 Bran sub3
4 97 Bryce sub6
5 88 Betty sub5 Process finished with exit code 0