在子集熊猫数据框时忽略KeyError

Question

我有一个熊猫数据框df，列city1，city2，city3，city4，city5。我有一个列表my_cities = [“city1”，“city3”，“city10”]。我想到子集根据my_cities.When我做列DF，

my_cities = [ “city1”， “请分享帮助”， “city10”]

df_my_cities = DF [my_cities]

我得到错误KeyError：“['city10']不在索引中”

如何判断代码是否继续执行，如果my_cities中的元素不在df中？

Answer 1

您可以使用所有列和list之间intersection：

df_my_cities = df[df.columns.intersection(my_cities)] 

样品：

df = pd.DataFrame({'city1':['s', 'e'], 
        'city2':['e','f'], 
        'city3':['f','g'], 
        'city4':['r','g'], 
        'city5':['t','m']}) 

print (df) 
    city1 city2 city3 city4 city5 
0  s  e  f  r  t 
1  e  f  g  g  m 

my_cities = ["city1","city3","city10"] 
df_my_cities = df[df.columns.intersection(my_cities)] 
print (df_my_cities) 
    city1 city3 
0  s  f 
1  e  g 

或者numpy.intersect1d：

df_my_cities = df[np.intersect1d(df.columns, my_cities)] 
print (df_my_cities) 
    city1 city3 
0  s  f 
1  e  g