pythonは文字列内のすべての数値の和を計算します.

'''
   ：            
1.             
2.      ，      
3.            
 ：'12abc34de5f' => 12 + 34 + 5 => 51
'''
def sum_of_num(s):

    m = 0

    sum = 0

    for i in range(len(s)):

        if ord(s[i]) >= 48 and ord(s[i]) <= 57:

            m = (m * 10) + int(s[i])                         #      

            #print(m)

        else:

            sum = sum + m

            m = 0

    if ord(s[-1]) >= 48 and ord(s[-1]) <= 57:
         
         sum = sum + m
           

    return sum



print(sum_of_num('12abc34de5s1s2f'))












#print(ord('0'),ord('9'))