将具有逗号分隔字符串的 2 列合并为 pandas 中的 1 列

Question

I have a dataframe

df = pd.DataFrame([["A","a$b,c$d,k$m","h,y,a"], ["B","n$e,d$w,t$y","t,r,s"]], columns=["id","c1","c2"])

I want to combine each element of column c1 which are separated by a comma with another element of column c2 with an asterisk(*)

Expected output:

df_out = pd.DataFrame([["A","a$b*h,c$d*y,k$m*a"], ["B","n$e*t,d$w*r,t$y*s"]], columns=["id","c3"])

How to do it?

Answer 1

You can try out the below code.

df = pd.DataFrame([["A","a$b,c$d,k$m","h,y,a"], ["B","n$e,d$w,t$y","t,r,s"]], columns=["id","c1","c2"])

def combine_list(a, b):
          return (',').join([i+'*'+j for i, j in zip(a, b)])
        
df['c3'] = df.apply(lambda x: combine_list(x['c1'].split(','), x['c2'].split(',')), axis=1)
df_out = df[["id", "c3"]]

Hope this solves your query!

Answer 2

Use nested list comprehension with DataFrame.pop for extract values and zip , for add * is used f-string s and last join in join :

df['c3'] = [','.join(f'{i}*{j}' for i, j in zip(x.split(','), y.split(',')))
                                for x, y in zip(df.pop('c1'), df.pop('c2'))]
print (df)
  id                 c3
0  A  a$b*h,c$d*y,k$m*a
1  B  n$e*t,d$w*r,t$y*s