import pandas as pd
import numpy as np
df = pd.DataFrame({'key1':list('aabba'),
'key2': ['one','two','one','two','one'],
'data1': ['1','3','5','7','9'],
'data2': ['2','4','6','8','10']})
print (df)
out:
key1 key2 data1 data2
0 a one 1 2
1 a two 3 4
2 b one 5 6
3 b two 7 8
4 a one 9 10
grouped = df.groupby(['key1']).size()
print(grouped)
out:
key1
a 3
b 2
dtype: int64
df["add"] = 1
print(df)
out:
key1 key2 data1 data2 add
0 a one 1 2 1
1 a two 3 4 1
2 b one 5 6 1
3 b two 7 8 1
4 a one 9 10 1
grouped = df.groupby(["key1"]).agg('sum').reset_index() #按key1的值分组,并统计个数
print (grouped)
out:
key1 add
0 a 3
1 b 2
grouped = df.groupby(["key1","data1"]).agg('sum').reset_index() #按key1的值分组,并统计个数
print (grouped)
out:
key1 data1 add
0 a 1 1
1 a 3 1
2 a 9 1
3 b 5 1
4 b 7 1
python里pandas里面groupby函数用法
猜你喜欢
转载自blog.csdn.net/yuekangwei/article/details/89373982
今日推荐
周排行