Pandas指定多列组合形成新列

1、数据准备

df = pd.DataFrame({'first_name': ['A', 'B'], 'last_name': ['a', 'b']})
print(df.to_string())
'''
  first_name last_name
0          A         a
1          B         b
'''

2、多列组合

2.1、方式一：使用cat()

df['full_name'] = df['first_name'].str.cat(df['last_name'].astype(str), sep='-')
print(df.to_string())
'''
  first_name last_name full_name
0          A         a       A-a
1          B         b       B-b
'''

2.2、方式二：使用map()

df['full_name'] = list(map(lambda c1, c2: c1 + '-' + c2, df['first_name'], df['last_name']))
print(df.to_string())
'''
  first_name last_name full_name
0          A         a       A-a
1          B         b       B-b
'''

2.3、方式三：直接组合

df['full_name'] = df['first_name'] + '-' + df['last_name']
print(df.to_string())
'''
  first_name last_name full_name
0          A         a       A-a
1          B         b       B-b
'''