如何在 pandas df col 中使用嵌套列表中的元素作为 if 语句条件

Question

It's such a weird question, I don't even know how to phrase it.

df looks like this:

col4
['df['col1'] == 10]', ['df['col2'] == 'cat']']
['df['col1'] == 20]', ['df['col3'] == 'some string']']

df1 looks like this:

col1    col2    col3
10      cat     some string
20      dog     some string

my goal is to use the elements in df.col4 as conditions in an if statement against another df ( df1 ).

output for df1.new_col i'm aiming for is:

col1    col2    col3          new_col
10      cat     some string   yes
20      dog     some string   yes
30      pet     some string   no

I appreciate all y'alls help.

Answer 1

You should look into query() . It allows you to do something like

df1.query("col1 == 10 & col3 == 'some string'")

which in this case would yield

   col1 col2         col3
0    10  cat  some string

and use the number of hits to populate the new_col column. But it requires you to reformat your conditions in df.col4 to something that is compatible with query() . Also I don't understand why you would keep those conditions as nested lists in a dataframe column, it looks wildly impractical to me.