比较两个数据框列，以检查他们是否有在python

Question

我有两个dataframes相同的值，

new1. 
     Name  city 
0 sri won chn 
1 pechi won pune 
2 Ram won mum 
0 pec won kerala 

new3 
    req 
0 pec 
1 mut 

我试过，

mask=new1.Name.str.contains("|".join(new3.req.values.tolist())) 
new1[mask] 

我得到，

new1[mask] 
     Name  city 
1 pechi won pune 
0 pec won  kerala 

由于“pechi”包含“pec”，它花了这个价值。但我想值之间的精确匹配不是“包含”

我期望的输出，

new1[mask] 
     Name  city 
0 pec won  kerala 

Answer 1

你需要\b，意思是“单词边界” ：

a = r'\b(' + "|".join(new3.req.values.tolist()) + r')\b' 
print (a) 
\b(pec|mut)\b 

mask=new1.Name.str.contains(a) 
df = new1[mask] 
print (df) 
     Name city 
0 pec won kerala 

Answer 2

您在分离器需要空间

In [1350]: new1 
Out[1350]: 
     Name city 
0 sri won  chn 
1 pechi won pune 
2 Ram won  mum 
0 pec won kerala 

In [1351]: new3 
Out[1351]: 
    req 
0 pec 
1 mut 

In [1352]: ' | '.join(new3.req) 
Out[1352]: 'pec | mut' 

In [1353]: new1.Name.str.contains(' | '.join(new3.req)) 
Out[1353]: 
0 False 
1 False 
2 False 
0  True 
Name: Name, dtype: bool 

In [1354]: new1[new1.Name.str.contains(' | '.join(new3.req))] 
Out[1354]: 
     Name city 
0 pec won kerala