Python 如何比较两个dataframe并根据条件填充列值？

您好，我正在尝试根据某些条件比较两个数据帧，并尝试填充列值。我没有得到理想的结果。你能帮帮我吗

例如：

df1:

PDF_FILE_Name                                         Indication
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_rec      
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_cgr
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_pfizer
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_kcc


df2:

PDF_FILE_Name                                         Indication
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_rec      Metastatic Renal Cell Carcinoma  
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_pfizer   Metastatic Renal Cell Carcinoma

In result I want below df
print(df1):

PDF_FILE_Name                                         Indication
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_rec      Metastatic Renal Cell Carcinoma  
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_cgr
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_pfizer   Metastatic Renal Cell Carcinoma
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_kcc

Series.map（）

df1['Indication']=df1['PDF_FILE_Name'].map（df2.set_index（'PDF_FILE_Name'）['Indication']））

或

merge（）

df1['Indication']=pd.merge（df1，df2，on='PDF_FILE_Name'）['Indication_y']

这是一个简单的

merge（）

PDF文件名 指示 0 PA0001000\u pcodr\u rfa\u axitinib\u inlyta\u mrcc\u rfa\u rec 转移性肾细胞癌 1. PA0001000\u pcodr\u rfa\u axitinib\u inlyta\u mrcc\u rfa\u cgr 楠 2. PA0001000\u pcodr\u rfa\u axitinib\u inlyta\u mrcc\u fdk\u辉瑞 转移性肾细胞癌 3. PA0001000\u pcodr\u rfa\u axitinib\u inlyta\u mrcc\u fdk\u kcc 楠

---

你试过合并吗

df1.merge（df2，on='PDF\u FILE\u Name'，how='left'）

df1 = pd.read_csv(io.StringIO("""PDF_FILE_Name                                         Indication
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_rec      
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_cgr
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_pfizer
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_kcc"""), sep="\s+")

df2 = pd.read_csv(io.StringIO("""PDF_FILE_Name                                         Indication
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_rfa_rec      Metastatic Renal Cell Carcinoma  
PA0001000_pcodr_rfa_axitinib_inlyta_mrcc_fdk_pfizer   Metastatic Renal Cell Carcinoma
"""), sep="\s\s+", engine="python")

df1.loc[:,["PDF_FILE_Name"]].merge(df2, on="PDF_FILE_Name", how="left")