使用python进行表计算[关闭]

Question

我的数据框看起来像 -

city            state           age
kolkata        west bengal       5
chennai        tamilnadu         7
mumbai         maharashtra       8
chennai        tamilnadu         8

我希望数据框看起来像 -

variable         city_name           count
city               kolkata             1
                   chennai             2
                   mumbai              1
state            west bengal           1
                 tamilnadu             2
                 maharashtra           1
age                  5                 1
                     7                 1
                     8                 2

如何在python中做到这一点？

Answer 1

我会这样做：

import pandas as pd
df = pd.DataFrame(columns=['city', 'state', 'age'])
df.loc[0] = ['kolkata', 'west bengal', 5]
df.loc[1] = ['chennai', 'tamilnadu', 7]
df.loc[2] = ['mumbai', 'maharashtra', 8]
df.loc[3] = ['chennai', 'tamilnadu', 8]

ct_df = pd.DataFrame(columns=['variable', 'value', 'count'])
index = 0
for col in df.columns:
    the-set = set(df[col])
    for element in the_set:
        count = len(df.loc[df[col] == element])
        ct_df.loc[index] = [col, element, count]
        index += 1

结果非常接近你想要的：

  variable        value count
0     city      chennai     2
1     city       mumbai     1
2     city      kolkata     1
3    state  maharashtra     1
4    state  west bengal     1
5    state    tamilnadu     2
6      age            8     2
7      age            5     1
8      age            7     1