如何合并 pandas 中的两列（附示例）

您可以使用以下语法将 pandas DataFrame 中的两个文本列合并为一个：

 df[' new_column '] = df[' column1 '] + df[' column2 ']

如果其中一列还不是字符串，您可以使用astype(str)命令将其转换：

 df[' new_column '] = df[' column1 ']. astype ( str )+df[' column2 ']

您可以使用以下语法将多个文本列合并为一个：

 df[' new_column '] = df[[' col1 ', ' col2 ', ' col3 ', ...]]. agg (' '. join , axis= 1 )

以下示例展示了如何在实践中组合文本列。

示例 1：合并两列

以下代码展示了如何在 pandas DataFrame 中将两个文本列合并为一列：

 import pandas as pd

#create dataFrame
df = pd. DataFrame ({' team ': ['Mavs', 'Lakers', 'Spurs', 'Cavs'],
                   ' first ': ['Dirk', 'Kobe', 'Tim', 'Lebron'],
                   ' last ': ['Nowitzki', 'Bryant', 'Duncan', 'James'],
                   ' points ': [26, 31, 22, 29]})

#combine first and last name column into new column, with space in between
df[' full_name '] = df[' first '] + ' ' + df[' last ']

#view resulting dataFrame
df

team first last points full_name
0 Mavs Dirk Nowitzki 26 Dirk Nowitzki
1 Lakers Kobe Bryant 31 Kobe Bryant
2 Spurs Tim Duncan 22 Tim Duncan
3 Cavs LeBron James 29 LeBron James

我们已经将名字和姓氏列连接在一起，中间有一个空格，但我们也可以使用不同的分隔符，例如连字符：

 #combine first and last name column into new column, with dash in between
df[' full_name '] = df[' first '] + ' - ' + df[' last ']

#view resulting dataFrame
df

team first last points full_name
0 Mavs Dirk Nowitzki 26 Dirk - Nowitzki
1 Lakers Kobe Bryant 31 Kobe - Bryant
2 Spurs Tim Duncan 22 Tim - Duncan
3 Cavs Lebron James 29 Lebron - James

示例 2：转换为文本并合并两列

以下代码显示如何将列转换为文本，然后将其连接到另一列：

 import pandas as pd

#create dataFrame
df = pd. DataFrame ({' team ': ['Mavs', 'Lakers', 'Spurs', 'Cavs'],
                   ' first ': ['Dirk', 'Kobe', 'Tim', 'Lebron'],
                   ' last ': ['Nowitzki', 'Bryant', 'Duncan', 'James'],
                   ' points ': [26, 31, 22, 29]})

#convert points to text, then join to last name column
df[' name_points '] = df[' last '] + df[' points ']. astype ( str )

#view resulting dataFrame
df

        team first last points name_points
0 Mavs Dirk Nowitzki 26 Nowitzki26
1 Lakers Kobe Bryant 31 Bryant31
2 Spurs Tim Duncan 22 Duncan22
3 Cavs LeBron James 29 James29

示例 3：合并两列以上

以下代码展示了如何将多列合并为一列：

 import pandas as pd

#create dataFrame
df = pd. DataFrame ({' team ': ['Mavs', 'Lakers', 'Spurs', 'Cavs'],
                   ' first ': ['Dirk', 'Kobe', 'Tim', 'Lebron'],
                   ' last ': ['Nowitzki', 'Bryant', 'Duncan', 'James'],
                   ' points ': [26, 31, 22, 29]})

#join team, first name, and last name into one column
df[' team_and_name '] = df[[' team ', ' first ', ' last ']]. agg (' '. join , axis= 1 )

#view resulting dataFrame
df

team first last points team_name
0 Mavs Dirk Nowitzki 26 Mavs Dirk Nowitzki
1 Lakers Kobe Bryant 31 Lakers Kobe Bryant
2 Spurs Tim Duncan 22 Spurs Tim Duncan
3 Cavs Lebron James 29 Cavs Lebron James

其他资源

Pandas：如何找到两列之间的差异
Pandas：如何找到两条线之间的差异
Pandas：如何按名称对列进行排序