从一个数据帧中复制行并根据条件转换为列（熊猫）

Question

我有一个 dataframe 为：（df1）

Filename    Name    1_Info1     1_Info2     1_Info3
Filename_1  Name1   First Row   01-01-1900  Information_1st Row
Filename_2  Name2   Second Row  01-01-1901  Information_2nd Row
Filename_3  Name3   Third Row   01-01-1902  Information_3rd Row

第二个dataframe为：df2（文件名）

Model       Sample_ID2  Location1   Location2   Location3
MODEL_1     ID          10          40          70
MODEL_2     ID          20          50          80
MODEL_3     ID          30          60          90
MODEL_4     ID          31          61          91
MODEL_5     ID          32          62          92
MODEL_6     ID          33          63          93

df2的Filename在df1的文件名列中匹配，如果匹配，则df1的信息应复制为df2中的列。

因此，如果文件名为“Filename_1”，output 应该如下所示。

Model   Sample_ID2  Location1   Location2   Location3   Filename            Name    1_Info1         1_Info2         1_Info3
MODEL_1 ID          10          40          70          Filename_1          Name1   First Row       01-01-1900      Information_1st Row
MODEL_2 ID          20          50          80          Filename_1          Name1   First Row       01-01-1900      Information_1st Row
MODEL_3 ID          30          60          90          Filename_1          Name1   First Row       01-01-1900      Information_1st Row
MODEL_4 ID          31          61          91          Filename_1          Name1   First Row       01-01-1900      Information_1st Row
MODEL_5 ID          32          62          92          Filename_1          Name1   First Row       01-01-1900      Information_1st Row
MODEL_6 ID          33          63          93          Filename_1          Name1   First Row       01-01-1900      Information_1st Row

文件名已经被提取并搜索并且行被连接但唯一的问题是在所有行中复制它（因为这仅在第一行中复制）

代码如下：

df1 = pd.read_csv("Filename_1.text.csv")
df2 = pd.read_csv("test_data.csv")

filename = os.path.basename("Filename_1.text.csv")
filename_new = filename.split('.')[0]

checked = ((df1[df1['Filename'] == filename_new]))

combined_df = pd.concat([df2, checked], axis=1)

Answer 1

通过使用ffill()解决：

df1 = pd.read_csv("Filename_1.text.csv")
df2 = pd.read_csv("test_data.csv")

filename = os.path.basename("Filename_1.text.csv")
filename_new = filename.split('.')[0]

checked = ((df1[df1['Filename'] == filename_new]))

combined_df = pd.concat([df2, checked], axis=1)
cols = ['Filename','Name','1_Info1','1_Info2','1_Info3']
combined_df.loc[:,cols] = combined_df.loc[:,cols].ffill()