Python | Sort numeric strings in a list



Method # 1: The Naive Method
The naive method requires the type conversion of all elements to integers in the list, iterated over in a loop. The general sorting function is then used to complete the task.

# Python3 demo code
# sorting numeric strings
# using the naive method

 
# initializing list

test_list = [ `4` , ` 6 ` , ` 7` , `2` , ` 1` ]

 
# print original list

  print ( "The original list is:" + str (test_list))

  
# using the naive method
# sorting numeric strings

for i in range ( 0 , len (test_list)):

  test_list [i] = int (test_list [i] )

test_list.sort ()

 
# print result

print ( "The resultant sorted list :" +   str ( test_list))

Exit:

 The original list is: [`4`,` 6`, `7`,` 2`, `1`] The resultant sorted list: [1, 2, 4, 6, 7] 

Method # 2: Using sort () with a key
A generic sort () can be used to accomplish this specific task, but must be specified with a key as an integer. to convert it to an integer when executing the inner sort function.

# Python3 demo code
# sorting numeric strings
# using sorting () + key

  
# initializing list

test_list = [ `4` , ` 6` , `7` , ` 2` , `1` ]

 
# print original list

print ( "The original list is:" + str (test_list))

  
# using sorting () + key
# sorting numeric strings

test_list.sort (key = int )

 
# print result

print ( "The resultant sorted list :" +   str (test_list))

Exit:

 The original list is: [`4`,` 6`, `7`,` 2`, `1`] The resultant sorted list: [` 1`, `2`,` 4`, `6`,` 7`] 

Method # 3: Using sorted () + key
This function has the same inner workings as above. The improvement this function offers over the aforementioned function is that it does not change the order of the original list and simply returns the displayed view, which is useful in situations where ordering needs to be maintained.

# Python3 demo code
# sorting numeric strings
# using sorted () + key

 
# initializing list

test_list = [ ` 4` , `6` , `7` , ` 2` , `1` ]

  
# print original list

print ( "The original list is:" + str (test_list))

 
# using sorted ( ) + key
# sorting numeric strings

res = sorted (test_list, key = int )

 
# print result

print (  "The resultant sorted list :" +   str (res))

Output:

 The original list is: [`4`,` 6`, `7`,` 2`, `1`] The resultant sorted list: [` 1`, `2`,` 4`, `6 `,` 7`]