如何將文本文件重新格式化爲具有給定線寬的新文件

Question

如何將文本文件重新格式化爲具有給定線寬的新文件？

例如：

示例文件input.txt：

Your program should store a single row of the triangle and calculate each subsequent row by adding a value to the values 
immediately above it and to its left. The values on each line must be space-separated. 

示例文件output.txt：

Your program should store a single row 
of the triangle and calculate each 
subsequent row by adding a value to the 
values immediately above it and to its 
left. The values on each line must be 
space-separated. 

樣品控制檯I/O：

Enter the input filename: 
input.txt 
Enter the output filename: 
output.txt 
Enter the line width: 
40 

Answer 1

使用textwrap.fill：

import textwrap 

text = '''Your program should store a single row of the triangle and calculate each subsequent row by adding a value to the values immediately above it and to its left. The values on each line must be space-separated.''' 

print(textwrap.fill(text, 40)) 

產生

Your program should store a single row 
of the triangle and calculate each 
subsequent row by adding a value to the 
values immediately above it and to its 
left. The values on each line must be 
space-separated.