4.py

# Python3 code to demonstrate working of
# Replace duplicate Occurrence in String
# Using split() + enumerate() + loop

# initializing string
test_str = 'Gfg is best . Gfg also has Classes now. \
				Classes help understand better . '

# printing original string
print("The original string is : " + str(test_str))

# initializing replace mapping
repl_dict = {'Gfg': 'It', 'Classes': 'They'}

# Replace duplicate Occurrence in String
# Using split() + enumerate() + loop
test_list = test_str.split(' ')
res = set()
for idx, ele in enumerate(test_list):
	if ele in repl_dict:
		if ele in res:
			test_list[idx] = repl_dict[ele]
		else:
			res.add(ele)
res = ' '.join(test_list)

# printing result
print("The string after replacing : " + str(res))