mmaul8

file = input("Input your file name coreectly : ")
#Input your file name with extention, example : file.txt
#It will work when you use it on same directory of your file
bef = input("What text you want to replace? ")
aft = input("Input your new text : ")

fin = open(file, "rt")
data = fin.read()
data = data.replace(bef,aft)
fin.close()

mmaul8

import os

basepath = input("Please input your specific directory : ")
#input example C:\Users\John\Downloads\
for entry in os.listdir(basepath):
	if os.path.isfile(os.path.join(basepath, entry)):
		print(entry)