Python - Splitting numbers and letters into sub-strings with regular expression

Question

I am creating a metric measurement converter. The user is expected to enter in an expression such as 125km (a number followed by a unit abbreviation). For conversio

Answer 1

Split a string into list of sub-string (number and others)

Using program:

s = "125km1234string"
sub = []
char = ""
num = ""
for letter in s:
    if letter.isdigit():
        if char:
            sub.append(char)
            char = ""
        num += letter
    else:
        if num:
            sub.append(num)
            num = ""
        char += letter
sub.append(char) if char else sub.append(num)
print(sub)

Output

['125', 'km', '1234', 'string']