为什么在写入文件时循环执行两次

如何解决为什么在写入文件时循环执行两次

我有2个文件abc.txt，cde.txt

abc.txt的内容为“这是abc文件” cde.txt的内容为“这是cde文件”

我正在尝试写入文件。但是内容写了两次 下面是代码

in_files = ['abc.txt','cde.txt']
out_files = ['abc_output.txt','cde_output.txt']
read_dict = {}
for file in in_files:
    with open(file,'r') as read_file:
        lines = read_file.readlines()
        read_dict[file] = lines
read_dict
for k,v in read_dict.items():
    for out in out_files: 
        with open(out,'w+') as write_file:
             for i in v:
                print(i)

输出

This is abc file
This is abc file
This is cde file
This is cde file

预期

This is abc file
This is cde file

解决方法

如果您将print(i)更改为print('writing to',write_file,i)，则会看到第一次打印“ 这是abc文件”是针对您写入 abc_output.txt ，第二次打印是针对何时输出到 cde_output.txt 。

您的预期输出在每个文件中只会显示一次。那是您想要的，还是只将“ 这是abc文件”输出到 abc_output.txt 和“ 这是cde文件”仅输出到 cde_output.txt ？如果是这种情况，您可能想要执行以下操作：

in_files = ['abc.txt','cde.txt']
out_files = ['abc_output.txt','cde_output.txt']
read_dict = {}
for in_f,out_f in zip(in_files,out_files):
    with open(in_f,'r') as read_file:
        lines = read_file.readlines()
    with open(out_f,'w+') as write_file:
         #write_file.writelines(lines)
        print(lines)

,

之所以发生这种情况，仅仅是因为您运行了两次外部循环（每个out文件一次），并且导致总共运行4次而不是两次。

read_dict = {'file1':'abc file','file2':'cde file'}
out_files = ['out1','out2']

for k,v in read_dict.items():
    for out in out_files:
        print(k,v)

在上面运行此代码，这将完全生成您在输出文件中得到的内容。

,

您添加的最后一个循环是不必要的，在此之前的循环使它运行了两次，因为它嵌套在for k,v in read_dict.items()循环下...

    in_files = ['abc.txt','cde.txt']
    out_files = ['abc_output.txt','cde_output.txt']
    read_dict = {}
    for file in in_files:
     with open(file,'r') as read_file:
        lines = read_file.readlines()
        read_dict[file] = lines
read_dict
for k,v in read_dict.items():
    for out in out_files: 
      with open(out,'w+') as write_file:
            print(v)
            break;