如何将多个用户输入放入一个文本文件中？

Question

这是我现在的代码

fname = input(">>Please Enter a file name followed by .txt ")
def writedata():
    i=0
for i in range(3):
    f = open(f"{fname}", 'w')
    stdname = input('>>\tStudent Name: \t')
    marks = input('>>\tMark for exam: \t')
    f.write(stdname)
    f.write("\n")
    f.write(marks)
f.close()

def main():
    writedata()

预期的输出

>> Please Enter a file name, followed by .txt: studentRecord.txt
>> Enter record for student 1 in the format of [1. Name, 2. Mark]:
>>       Student Name: James White
>>       Mark for exam: 100
>> Enter record for student 2 in the format of [1. Name, 2. Mark]:
>>       Student Name: James Brown
>>       Mark for exam: 85
>> Enter record for student 3 in the format of [1. Name, 2. Mark]:
>>       Student Name: James King
>>       Mark for exam: 75
>> Student record writing completed!

我尝试了上面的代码，只得到了文本文件中的最后一个用户输入。我应该从 def main() 传递文件名，但我不知道该怎么做，我一直收到无法访问的错误。有人可以帮助我并解释我做错了什么吗？感谢您的时间和考虑。

Answer 1

请注意

    f = open(f"{fname}", 'w')

您正在使用 w 模式，每次都会覆盖文件。相反，使用 a+ 模式，它附加到文件，如果文件尚不存在则创建文件。

Answer 2

您正在使用 write (w) 文件方法，它会用您传递的任何新数据覆盖您的文件。您需要 append (a) file 方法，它每次都会附加到您的文件中。

The BSD fopen manpage定义文件方法如下：

The argument mode points to a string beginning with one of the following
 sequences (Additional characters may follow these sequences.):

 ``r''   Open text file for reading.  The stream is positioned at the
         beginning of the file.

 ``r+''  Open for reading and writing.  The stream is positioned at the
         beginning of the file.

 ``w''   Truncate file to zero length or create text file for writing.
         The stream is positioned at the beginning of the file.

 ``w+''  Open for reading and writing.  The file is created if it does not
         exist, otherwise it is truncated.  The stream is positioned at
         the beginning of the file.

 ``a''   Open for writing.  The file is created if it does not exist.  The
         stream is positioned at the end of the file.  Subsequent writes
         to the file will always end up at the then current end of file,
         irrespective of any intervening fseek(3) or similar.

 ``a+''  Open for reading and writing.  The file is created if it does not
         exist.  The stream is positioned at the end of the file.  Subse-
         quent writes to the file will always end up at the then current
         end of file, irrespective of any intervening fseek(3) or similar.