turn "string-like" list into int with python

Question

After after retrieving some data, some rows of my dataframe are composed by "string-like" lists, like this one:

       bar                foo
   0     'A'                1
   1     'B'                2
   2     'B'     "['2' ,'3']"
   3     'B'              '4'
   4     'C'     "['5' ,'3']"

How could I turn the foo column into int values and take the bigger value with python pandas?

Answer 1

警告。这有点手册；

df['foo']=df['foo'].str.strip("''")#Strip ''
df['foo']=np.where(df['foo'].str.contains('\['),df['foo'].str.findall('(?<=\"\[\')\d(?=\'\,)|(?<=\')\d(?=\'\]\")'),df['foo'])# Extract digits sandwitched between special characters
df['foo']=df['foo'].explode().max(level = 0)



  bar foo
0  'A'   1
1  'B'   2
2  'B'   3
3  'B'   4
4  'C'   5