"""笨办法学python，启动时在命令行中python 脚本文件名 filename""" from sys import argv # argv  - 命令行参数; argv[0]是脚本路径名python,sys.argv[0]表示脚本路径名 script, filename = argv         # 脚本和文件名称 print("We're going to erase %r." % filename)    # 正常使用%s，在这里%r是为了重现它代表的对象 print("If you don't want that, hit RETURN-C (^C).") print("If you do want that, hit RETURN.") input("?")                  # 单纯的？号 print("Opening the file...") target = open(filename, "w")    # 以"w"写入的形式打开文件，a表示追加，r表示读取。不写默认是读取操作 print("Truncating the file. Goodbye!") target.truncate()           # 清除之前的数据 print("Now I'm going to ask you for three lines.") line1 = input("line 1: ")       # 获取用户输入 line2 = input("line 2: ") line3 = input("line 3: ") print("I'm going to write these to the file.") target.write(line1)             # 写入用户输入 target.write("\n") target.write(line2) target.write("\n") target.write(line3) target.write("\n") print("And finally, we close it.") target.close()              # 关闭已打开的文件