[SOLVED] How to extract numbers from a string that has no spaces into a list

How to extract numbers from a string that has no spaces into a list

I have an assignment for which my script should be able to receive a string for input (e.g. "c27bdj3jddj45g" ) and extract the numbers into a list (not just the digits, it should be able to detect full numbers). I am not allowed to use regex at all, only simple methods like split, count and append. Any ideas? (Using python)

Example for the output needed for the string I gave as an example: ['27','3', '45']

Nothing I have tried so far is worth mentioning here, I am pretty lost on which approach to take here without re.findall, which I cannot use.

Solution

You can do this with a for-loop and save the numbers. Then, when you see no digit, append digits and reset the string.

s = 'g38ff11'
prv = ''
res = []
for c in s:
    if c.isdigit():
        prv += c
    else:
        if prv != '': res.append(prv)
        prv = ''
if prv != '': res.append(prv)
print(res)

Output:

['38', '11']

You can also write a lambda to check and append:

s = 'g38ff11'
prv = ''
res = []
append_dgt = lambda prv, res: res.append(prv) if prv!=""  else None
for c in s:
    if c.isdigit():
        prv += c
    else:
        append_dgt(prv,  res)
        prv = ''
append_dgt(prv, res)
print(res)