python读文件逐行处理的示例代码分享

import os ## for os.path.isfile()

def dealline(line) :
print(line) ## 针对line我可以做很多事情

def getfilename() :
return input('Please input file name(input exit() for exit):').strip()

class more : ## MORE功能
linenum = 0
size = 10
def work(self) :
if self.linenum >= self.size :
if input('--MORE--').strip().lower() == 'exit()' :
return False
self.linenum = 0
else :
self.linenum += 1
return True

while True :
try :
filename = getfilename()

if filename.lower() == 'exit()' : ## 退出
break

if os.path.isfile(filename) : ## 判断文件是否存在

f = open(filename)
try :
lines = f.readlines()

m = more()
for line in lines:
if False == m.work() :
break
dealline(line)

## input()
finally :
f.close()

else :
print('File does not exists.')
##input()
except :
print('Input Error!')

代码如下:

with open(filename) as fh:
for line in fh:
yield line