Dataframe 包含到 CSV 的嵌套列表

Question

I have a dataframe which has nested lists as column values like given below:

    col1         col2   
0   [1, 1]      [a, b, c]   
1   [0, 0, 0]   [d, e, f]   

When I convert the dataframe to csv, I get something like this:

   col1      col2   
  [1 1]  ,  [a b c] 
  [0 0 0] , [d e f] 

Basically, the commas from the nested lists disappear and when I read back the dataframe from csv I don't get the commas. How can I maintain the commas and save the csv to something like this:

   col1          col2   
  [1,1]    ,    [a, b, c]   
  [0, 0, 0] ,   [d, e, f]   

PS: I would like a pandas solution to creating the csv

Answer 1

I think there are not lists, but arrays, so if write to csv comma are removed:

df = pd.DataFrame({'col1':[np.array([1,1]), np.array([0,0,0])]})
print (df)
        col1
0     [1, 1]
1  [0, 0, 0]

df.to_csv('file.csv', index=False)

df = pd.read_csv('file.csv')
print (df)
      col1
0    [1 1]
1  [0 0 0]

Possible solution is convert arrays to lists:

df = pd.DataFrame({'col1':[np.array([1,1]), np.array([0,0,0])]})

df = df.applymap(list)
print (df)
        col1
0     [1, 1]
1  [0, 0, 0]

df.to_csv('file.csv', index=False)

df = pd.read_csv('file.csv')
print (df)
        col1
0     [1, 1]
1  [0, 0, 0]

Last for lists from string representation of lists use:

import ast

df = df.applymap(ast.literal_eval)
print (df)
        col1
0     [1, 1]
1  [0, 0, 0]