我試圖強調兩個數據框之間的確切變化。
假設我有兩個Python Pandas數據框:
"StudentRoster Jan-1":
id Name score isEnrolled Comment
111 Jack 2.17 True He was late to class
112 Nick 1.11 False Graduated
113 Zoe 4.12 True
"StudentRoster Jan-2":
id Name score isEnrolled Comment
111 Jack 2.17 True He was late to class
112 Nick 1.21 False Graduated
113 Zoe 4.12 False On vacation
我的目標是輸出一個HTML表格:
- 標識已更改的行(可以是int,float,boolean,string)
- 輸出具有相同,舊和新值的行(理想情況下放入HTML表格中),以便用戶可以清楚地看到兩個數據框之間的變化:
"StudentRoster Difference Jan-1 - Jan-2": id Name score isEnrolled Comment 112 Nick was 1.11| now 1.21 False Graduated 113 Zoe 4.12 was True | now False was "" | now "On vacation"
第一部分與Constantine相似,你可以得到其中行爲空的布爾值*:
In [21]: ne = (df1 != df2).any(1)
In [22]: ne
Out[22]:
0 False
1 True
2 True
dtype: bool
然後我們可以看到哪些條目已經改變:
In [23]: ne_stacked = (df1 != df2).stack()
In [24]: changed = ne_stacked[ne_stacked]
In [25]: changed.index.names = ['id', 'col']
In [26]: changed
Out[26]:
id col
1 score True
2 isEnrolled True
Comment True
dtype: bool
這裏第一項是索引,第二項是已更改的列。
In [27]: difference_locations = np.where(df1 != df2)
In [28]: changed_from = df1.values[difference_locations]
In [29]: changed_to = df2.values[difference_locations]
In [30]: pd.DataFrame({'from': changed_from, 'to': changed_to}, index=changed.index)
Out[30]:
from to
id col
1 score 1.11 1.21
2 isEnrolled True False
Comment None On vacation
注意:df1
並且df2
共享相同的索引。爲了克服這種模糊性,可以確保你只使用共享標籤df1.index & df2.index