Question

让我们假设我有一个像这样的Pandas Dataframe：

   C1    C2    C3
0  1     B     v
1  5     D     i
2  1     B     iii
3  3     C     iv

C1，C2，C3的所有可能值都是

C1 = [1,2,3,4,5]
C2 = ['A','B','C','D','E']
C3 = ['i','ii','iii','iv','v']

问题是打印新行以排除现有数据帧中尚未存在的C1，C2，C3的所有可能组合。

有没有比使用C1，C2，C3的所有值并将每个组合与现有列表进行比较的3个嵌套循环更好的方法？

Answer 1

你可以尝试这样的事情，

C1 = [1, 2, 3, 4, 5]
C2 = ['A', 'B', 'C', 'D', 'E']
C3 = ['i', 'ii', 'iii', 'iv', 'v']
existing = ((1, 'B', 'v'), (5, 'D', 'i'), (1, 'B', 'iii'), (3, 'C', 'iv'))

import itertools
result = [i for i in itertools.product(C1, C2, C3) if i not in existing]

Answer 2

series_1 = pd.Series(C1)
new_data_frame['C1'] = series_1.values
series_2 = pd.Series(C2)
new_data_frame['C2'] = series_2.values
series_3 = pd.Series(C3)
new_data_frame['C3'] = series_3.values
for index, row in new_data_frame.iterrows():
    if existing_dataframe[existing_dataframe == row].shape[0] == 0:
         existing_dataframe.appen(row)

从可能的列值列表中创建新的唯一行

2 个答案: