创建一个函数来遍历现有数据框并将值添加到新列

Question

I have a data frame with the following information:

import pandas as pd
df = pd.DataFrame(data={'School':['A', 'B', 'C', 'D'],
                        'Year':[2009, 2010, 2011, 2012})

df
School   Year
A        2009
B        2010
C        2011
D        2012

I also have a separate list of schools (eg df2 = pd.DataFrame(data={'School':['A', 'B']}) ) stored in a different dataframe.

I want to create a function that will loop through the school column and add True or false to a new column if the school is in the list.

How do I do this?

Answer 1

您可以使用熊猫系列isin方法：

df['in_list'] = df['School'].isin(df2['School'])