Delete and Paste
To delete part of a string, you need to compose a new string by combining the parts of the original string before and after the section to be deleted.
s = "0123456789"
s1 = s[:3]+s[9:] # s1="0129"
Using slices and string concatenation, you can insert a substring inside a string.
s = "0123456789"
s1 = s[:3]+"ABC"+s[3:] # s1="012ABC3456789"