Find the index of the first digit in a string

Question

I have a string like

"xdtwkeltjwlkejt7wthwk89lk" 

how can I get the index of the first digit in the string?

Answer 1

Use re.search():

>>> import re >>> s1 = "thishasadigit4here" >>> m = re.search(r"\d", s1) >>> if m: ...     print("Digit found at position", m.start()) ... else: ...     print("No digit in that string") ...  Digit found at position 13 

Answer 2

Here is a better and more flexible way, regex is overkill here.

s = 'xdtwkeltjwlkejt7wthwk89lk'  for i, c in enumerate(s):     if c.isdigit():         print(i)         break 

output:

15 

To get all digits and their positions, a simple expression will do

>>> [(i, c) for i, c in enumerate('xdtwkeltjwlkejt7wthwk89lk') if c.isdigit()] [(15, '7'), (21, '8'), (22, '9')] 

Or you can create a dict of digit and its last position

>>> {c: i for i, c in enumerate('xdtwkeltjwlkejt7wthwk89lk') if c.isdigit()} {'9': 22, '8': 21, '7': 15}