 # Python | Convert list of numeric string to list of integers

Method # 1: Using List Comprehension
This problem can be solved by using list comprehension as a reduction in the general cycles that we would have to go through to accomplish this particular task, repeating each the line character of each list and converting to an integer.

 ` # Python3 demo code ` ` # converting a list of strings to a list of integers ` ` # using comprehension list ` `   # initializing list ```` test_list = [[ `24` ], [ `45` ], [ ` 78` ], [ `40` ]]   # print original list print ( "The original list:" + str (test_list))   # using comprehension list # converting string list to list of integers res = [[ int (i) for i in sub] for i in test_list for sub in i]   # print result print ( "The list after conversion:" + str ( res)) ```

Output:

` The original list: [[`24`], [` 45`], [`78`], [` 40`]] The list after conversion: [[2, 4], [4, 5], [7, 8], [4, 0]] `

Method # 2: Using ` map () ` + list comprehension
Problem executed in the above function can also be scaled down to include a display function that associates the conversion to integer with the function and the rest of the task is done the list comprehension function itself.

 ` # Python3 demo code ` ` # convert a list of strings to a list integers ` ` # using a list comprehension + map () `   ` # initializing list ` ` test_list ` ` = ` ` [[` ` `24` ` `], [` ` `45` ` `], [` `` 78` ` `] , [` ` `40` ` `]] ` ` `  ` # print original list ` ` print ` ` (` ` "The original list:" ` ` + ` ` str ` ` (test_list)) `   ` # using comprehension list + map () ` ` # convert a list of strings to a list of integers ` ` res ` ` = ` ` [` ` list ` ` (` ` map ` ` (` ` int ` `, ` ` list ` ` (sub [` ` 0 ` `]))) ` ` for ` ` sub ` ` in ` ` test_list ` ` if ` ` sub] ` ` `  ` # print result ` ` print ` ` (` ` "The list after conversion:" ` ` + ` ` str ` ` (res)) `

Output:

` The original list: [[`24`], [` 45`], [`78`], [` 40`]] The list after conversion: [[2, 4], [4, 5], [7, 8], [4, 0]] `