同时循环以不断重新检查数据帧中的更改

Question

我有两个相同的数据帧new和old。new数据帧将在一天中随机更新。下面的代码检查是否有任何更改

import pandas as pd
import numpy as np

new = {'name': ['Sheldon', 'Penny', 'Amy', 'Bernadette', 'Raj', 'Howard'],
                'episodes': [42, 24, 31, 29, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}
old = {'name': ['Sheldon', 'Penny', 'Amy', 'Bernadette', 'Raj', 'Howard'],
                'episodes': [12, 32, 31, 32, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}    

df1 = pd.DataFrame(new, columns = ['name','episodes', 'gender'])    
df = pd.DataFrame(old, columns = ['name','episodes', 'gender'])

while True:
    df1 = pd.DataFrame(new, columns = ['name','episodes', 'gender'])    
    print(df[~df.episodes.eq(df1.episodes)])
    df1 = df

我需要在while循环中写入条件，其中df[~df.episodes.eq(df1.episodes)]仅在检测到更改时才打印。打印新数据后，它会将两个数据框设置为相同的值（因为不再需要旧数据），并重新检查更改。上述代码将打印：

Columns: [name, episodes, gender]
Index: []
Empty DataFrame
Columns: [name, episodes, gender]
Index: []
Empty DataFrame
Columns: [name, episodes, gender]
Index: []
Empty DataFrame

因此，如果实际打印了更改，则可能会遗漏。你能建议一种更有效的方法来完成这项工作吗

==编辑==

根据@BENY的回答，如果我这样做：

import pandas as pd
import numpy as np

new = {'name': ['Sheldon', 'Penny', 'Amy', 'Bernadette', 'Raj', 'Sheldon'],
                'episodes': [42, 24, 31, 29, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}
old = {'name': ['Sheldon', 'Penny', 'Amy', 'Bernadette', 'Raj', 'Sheldon'],
                'episodes': [12, 32, 31, 32, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}    

df1 = pd.DataFrame(new, columns = ['name','episodes', 'gender'])    
df = pd.DataFrame(old, columns = ['name','episodes', 'gender'])

while True:
    df1 = pd.DataFrame(new, columns = ['name','episodes', 'gender'])    
    out = df.merge(df1[['name','episodes']],on=['name','episodes'],how='left',indicator=True).loc[lambda x : x['_merge']=='left_only']
    print(out)
    df = df1

它会在整个whileloop过程中打印出来：

         name  episodes  gender     _merge
0     Sheldon        12    male  left_only
1       Penny        32  female  left_only
3  Bernadette        32  female  left_only
         name  episodes  gender     _merge
0     Sheldon        12    male  left_only
1       Penny        32  female  left_only
3  Bernadette        32  female  left_only
         name  episodes  gender     _merge
0     Sheldon        12    male  left_only
1       Penny        32  female  left_only
3  Bernadette        32  female  left_only

有没有办法只打印一次。直到有另一个变化。如果idf= df1，它将按如下方式打印，我将错过更改：

Columns: [name, episodes, gender, _merge]
Index: []
Empty DataFrame
Columns: [name, episodes, gender, _merge]

我需要在检测到更改的地方干净地获取这些数据

Answer 1

让我们试试merge

out = df.merge(df1[['name','episodes']],on=['name','episodes'],how='left',indicator=True).loc[lambda x : x['_merge']=='left_only']
         name  episodes  gender     _merge
0     Sheldon        12    male  left_only
1       Penny        32  female  left_only
3  Bernadette        32  female  left_only