首页 > 编程语言 > 详细

Python 文件和异常

时间:2017-10-28 23:05:27      阅读:311      评论:0      收藏:0      [点我收藏+]

一、从文件中读取数据

 

#!/usr/bin/env python

with open(‘pi‘) as file_object:
    contents = file_object.read()
    print(contents)


===================================
3.1415926
  5212533
  2324255

 

1、逐行读取

#!/usr/bin/env python

filename = ‘pi‘

with open(filename) as file_object:
    for line in file_object:
        print(line)


===================================
3.1415926

  5212533

  2324255

 

#!/usr/bin/env python

filename = ‘pi‘

with open(filename) as file_object:
    for line in file_object:
        print(line.rstrip())

==================
3.1415926
  5212533
  2324255

 

2、创建一个包含文件各行内容的列表

#!/usr/bin/env python

filename = ‘pi‘

with open(filename) as file_object:
    lines = file_object.readlines()     #readlines()方法是从文件中读取每一行,并将其存储在一个列表中

for line in lines:
    print(line.rstrip())

==============================
3.1415926
  5212533
  2324255

 

3、使用文件内容

#!/usr/bin/env python

filename = ‘pi‘

with open(filename) as file_object:
    lines = file_object.readlines()

pi_string = ‘‘
for line in lines:
    pi_string += line.strip()

print(pi_string)
print(len(pi_string))

========================================
3.141592652125332324255
23

 

二、写入文件

1、写入空文件

#!/usr/bin/env python

filename = ‘programming.txt‘

with open(filename,‘w‘) as file_object:
    file_object.write("I love programming!")

2、写入多行

#!/usr/bin/env python

filename = ‘programming.txt‘

with open(filename,‘w‘) as file_object:
    file_object.write("I love programming!\n")
    file_object.write("yes!\n")

3、附加到文件

#!/usr/bin/env python

filename = ‘pi‘

with open(filename,‘a‘) as file_object:
    file_object.write("I love programming!\n")
    file_object.write("yes!\n")

 

三、异常

1、使用try-except代码块

#!/usr/bin/env python

try:
    print(5/0)
except ZeroDivisionError:
    print("You cant divide by zero!")

 

Python 文件和异常

原文:http://www.cnblogs.com/caicairui/p/7748380.html

(0)
(0)
   
举报
评论 一句话评论(0
关于我们 - 联系我们 - 留言反馈 - 联系我们:wmxa8@hotmail.com
© 2014 bubuko.com 版权所有
打开技术之扣,分享程序人生!