python文字列から数値を抽出して和を求める

s = "i13love14you520"
new_str = ""  		#        
for ch in s:
	if ch.isdigit():		#       ，      ch     
		new_str += ch
	else:
		new_str += " "
sub_list = new_str.split()   #        
num_list = list(map(int, sub_list)) 	#map  ，               
res  =sum(num_list)
print(res)

s = "i13love14you520"
new_str = ""  		#        
for ch in s:
	if ch.isdigit():		#       ，      ch     
		new_str += ch
	else:
		new_str += " "
sub_list = new_str.split()
print(sub_list)
ex_str = "+".join(sub_list)	#  join()       
print(eval(ex_str))

import re
re_obj = re.compile(r"\d+")		#         
res_list = re_obj.findall(s)		#  findall              
num_list = list(map(int, res_list))		#map  ，               
print(sum(num_list))