Define a function using a for loop called digit_sum() which takes a string and returns the sum of all the digits in the string, ignoring any characters which aren\'t digits. Solution Intially i want to built a function that has an array consisting of only numbers in it and making alphabets and symbols as 0 in value so that we can add the array in easy way Code: import re X=input(\"Input your string that may contain numbers and alphabets :\") Y=list(X) z=len(Y) myList=[] def digit_sum(): for i in range(z): Number=Y[i] myList.append((re.sub(\"[^0-9]\",\"0\",Number))) print(myList) digit_sum() Make the addition part...