15 阅读文件

from sys import argv script, filename = argv txt = open(filename) print(f"Here's your file {filename}:") print(txt.read()) print("Type the filename again:") file_again = input(">") txt_again = open(file_again) print(txt_again.read()) takekensakai@Starrys-MacBook-Pro 笨方法学python3 % python3 15.py ex15_sample.txt Here's your file ex15_sample.txt: This is stuff I typed into a file. It is really cool stuff. Lots and lots of fun to have in here. Type the filename again: >ex15_sample.txt This is stuff I typed into a file. It is really cool stuff. Lots and lots of fun to have in here.

16 读写文件

close - 关闭文件 truncate - 清空文件。清空的时候要当心。truncate() 对于 'w' 参数来说是必须的！！！

我能对文件使用哪些修饰符？目前最重要的一个就是 + ，你可以用 ‘w+’ ， ‘r+’ 以及 ‘a+’ 。这样会让文件以读和写的模式打开，取决于你用的是那个符号以及文件所在的位置等。

write('stuff') - 给文件写入一些“东西”。 write 命令需要你提供一个你要写入的文件的字符串参数。