python程序读取文件并打印文件的前两行和最后两行

你正在读前4行。你需要通读它们,只保留最后两个。

保存最后两行代码:

line1 = f1.readline()
line2 = f1.readline()

last1, last2 = f1.readline(), f1.readline()
while True:
    line = f1.readline()
    if not line:  # eof
        break
    last1, last2 = line, last1

print("Output:",line1,line2,last2,last1, sep= "")

例如,使用文件 test.txt :

Line1
line2
Line3
line4
Line5
line6
last line, line 7

Output:Line1
line2
line6
last line, line 7