isdigit python

s='12'
s.isdigit()#returns True

 txt = "50800"

x = txt.isdigit()

print(x) 

Non-zero integer ( x > 0 )	Argument is a numeric character.
Zero (0)	Argument is not a numeric character.

string.isdigit() how to remove a integer from a string

>>> my_list= ['image101.jpg', 'image2.jpg', 'image1.jpg']
>>> my_list.sort(key=lambda x: int(''.join(filter(str.isdigit, x))))
>>> my_list
['image1.jpg', 'image2.jpg', 'image101.jpg']

from natsort import natsorted
my_list = ['image101.jpg', 'image2.jpg', 'image1.jpg']
natsorted(my_list)

>>> ''.join(filter(str.isdigit, 'image101.jpg'))
'101'
>>> int(''.join(filter(str.isdigit, 'image101.jpg')))
101