python文件读取与输出_Python文件读取 并按格式输出文件内容

1. 切换工作目录

代码：

import os

os.chdir('D:/') # 注意斜杠方向

print(os.getcwd())

输出：

D:\

2. 打开文件open()

代码：

try:

data = open('sketch.txt')

print(data.readline(), end='') # 读取一行内容

print(data.readline(), end='') # 读取二行内容

data.seek(0) # 返回文件起始位置

except IOError:

print('The data file is missing!')

输出：

Man: Is this the right room for an argument?

Other Man: I've told you once.

0

3. 输出所有内容

代码：

for each_line in data:

try:

(role, line_spoken) = each_line.split(':', 1)

print(role, end='')

print(' said: ', end='')

print(line_spoken, end='')

except ValueError: # 因为数据中存在多个冒号和没有冒号的数据，需要处理产生的错误，

print(each_line)

部分输出：

Man said: Is this the right room for an argument?

Other Man said: I've told you once.

... ...

Man said: (exasperated) Oh, this is futile!!

Other Man said: No it isn't!

Man said: Yes it is!

4. 关闭文件

代码：

if 'data' in locals():

data.close()

# 或者使用with打开文件，则不需要手动close：

with open('sketch.txt', 'w') as data:

5. 完整代码

try:

with open('sketch.txt') as data:

for each_line in data:

try:

(role, line_spoken) = each_line.split(':', 1) # split('', 1)处理多个冒号的情况，只分一次；

print(role, end='')

print(' said: ', end='')

print(line_spoken, end='')

except ValueError: # 因为数据中存在没有冒号的数据，需要处理产生的错误；

print(each_line)

except IOError as err:

print('IOError: ' + str(err))