read、readline()、readlines()

1、read

将整个文件读取成一个字符串

2、f

for line in f:

每次读取一行

3、readline

line = f.readline()
while line:
    print(line.strip())
    line = f.readline()

每次读取一行

4、readlines

for line in f.readlines():
    print(line.strip())

每次读取一行