Using same string and replacing different names

Question

import re

str = "My name is David. Hi David.Amy is my name"
pattern = r"David"
pattern1= r"Amy"
newstr = re.sub(pattern, "Amy", str,1)
str2= re.sub(pattern1, "David", str)
print(newstr)
print(str2)

Answer 1

If your goal is to switch the names then this will do:

str = "My name is David. Hi David. Amy is my name"
pattern = r"(David)(.*)(Amy)"
newstr = Iregex.sub(pattern, r"\3\2\1", str)
print(newstr)