我有一个4个网站名称的文件,如下所示。我想在特定的时间间隔内,逐个连续打印每个网站的名称。
sample.txt:
facebook.com
gmail.com
test.com
yahoo.com
我已经尝试了以下代码。但它的印刷版网站只命名一次。我想不停地找名字
from time import sleep
while True:
with open ("sample.txt", 'r') as test:
while True:
print test.readline()
sleep(3)
pass
预期输出:facebook.com
gmail.com
test.com
yahoo.com
facebook.com
gmail.com
test.com
yahoo.com
facebook.com
gmail.com
test.com
yahoo.com
facebook.com
gmail.com
test.com
yahoo.com
.
.
.
我可以得到帮助来解决这个问题吗?
谢谢。
问题是,在readline()
到达文件末尾后,它将继续返回空行。你需要一些结束循环的东西,这样你就可以从文件的开头重新开始:
from time import sleep
while True:
with open ("sample.txt", 'r') as test:
for line in test:
print line.rstrip()
sleep(3)
如果您真的想使用readline
,那么您需要测试文件的结尾。当readline
读取实际行时,它将始终至少返回一个换行符。如果它不返回任何内容,那么它就到达了文件的末尾。因此:
from time import sleep
while True:
with open ("sample.txt", 'r') as test:
while True:
line = test.readline()
if not line:
break
print line.rstrip()
sleep(3)
返回迭代器的文件对象在第一轮调用readline()
后耗尽。相反,您应该将整个文件读入一个列表,并依次遍历该列表。
from time import sleep
with open ("sample.txt") as test:
lines = test.readlines() # read all lines into list
while True:
for line in lines:
print line
sleep(3)
你只需要在每行上循环:
for line in test:
print line
代替while True:
完成:
from time import sleep
with open ("sample.txt", 'r') as test:
for line in test
print line
sleep(3)