Question

我要查找的目标或输出是将输入txt文件追加到现有输入文件的所有行的第一部分。举个例子：

Input:
line_item1 string1
line_item2 string2
line_item3 string3

Output:
line_item1 string1
line_item2 string2
line_item3 string3
line_item1   # append
line_item2   # append
line_item3   # append

我创建的代码没有输出任何内容：

portionA = []
with open('output outfile.txt', "a+") as f:
    for line in f.readlines():
        parts = line.strip().split("\t", 1)
        portionA = parts[0]
        portionB = parts[1]
        portionA.append(line)
        f.write('{}\n'.format(''.join(portionA)))

Answer 1

您可以尝试：

with open('output outfile.txt', "a+") as f:
    for line in f.readlines():
        parts = line.strip().split("\t")
        f.write('{}\n'.format(parts[0]))

Answer 2

你应该使用'r +'而不是'a +'。

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

{+ 3}}

讨论为什么+ +不起作用

我无法更正f.write代码的缩进，所以这里是更正后的片段（注意用\ n而不是空字符串连接）

writeList= []
with open('outfile.txt', "r+") as f:
    for line in f:
        parts = line.strip().split("\t", 1)
        portionA = parts[0]
        portionB = parts[1]
        writeList.append(line)
    f.write('{}\n'.format('\n'.join(writeList)))

Python：追加拆分列表为空

2 个答案: