How I can reverse numbers in a string without reversing any text? [closed]

Question

I have a string, I need to reverse just the numbers in the string without the text:

String: [321 test]

The result will be: [123 test]

Answer 1

Something like this should work:

def reverse(s):
    items = s.split()
    digs = ''.join(i for i in s if i.isdigit())
    dr = digs[::-1]
    return ' '.join(map(None, items)).replace(digs, dr)

>>> reverse('321 test')
'123 test'

@mnpeterson brought up a good point about assuming where the numbers are...My post above would string all digits together even if they were separated so below is an edited version that would work better:

def reverse(s):
    items = str(s).split()
    dr = []
    for it in items:
        d = ''.join(i for i in it if i.isdigit())
        if d != '':
            dr.append(d[::-1])
        else:
            dr.append(it)
    return ' '.join(dr)

tests = ['321 test', 'test test 7868', '1234 test 7890 test', 'test test 1',
         'test test test', '123 321 456 test 98089897 test']
for t in tests:
    print reverse(t)

this printed:

123 test
test test 8687
4321 test 0987 test
test test 1
test test test
321 123 654 test 79898089 test

Answer 2

This function should work in field calculator (if your text is always after the numbers with a empty space):

def rev(x): 
  try:
    nonValue = x.split(' ')[1]
    value = ''.join(i for i in x if i.isdigit())[::-1]
    return value + ' ' + nonValue
  except ValueError:
    pass

Output e.g.: