NFA2

#bai4
 import re
 f = open("B1.txt")
 S = f.read().split("\n")
 for e in S:
     if re.search(r"\bregular\b", e):
         print(e)
 f.close()

#Bai 5
 import re

 f = open("B1.txt")
 S = f.read().split("\n")
 for e in S:
      print(e)
     rs = re.search(r"(?<=@).+", e)
     if rs:
        print(rs.group())
 f.close()
 
 #Bài 6 
import re

f = open("test3.csv")
S = f.read().split("\n")
for e in S:
    print(re.sub(r"([0-9]{2})\.([0-9]{2})\.([0-9]{4})", r"\2/\1/\3", re.sub(r"([0-9]{2})([0-9]{2})([0-9]{4})", r"\2/\1/\3", e)))
f.close()