使用Python在.txt文件的每一行中附加特定字符串

Question

我有一個.txt文件，其格式如下：

/Users/my_user/folder1/myfile.dat
/Users/my_user/folder2/myfile.dat
/Users/my_user/folder3/myfile.dat
.
.
.
so on

我想在每行的末尾附加另一個文件夾路徑，以使其看起來像這樣：

/Users/my_user/folder1/myfile.dat,/Users/my_user/folder1/otherfile.dat
/Users/my_user/folder2/myfile.dat,/Users/my_user/folder1/otherfile.dat
/Users/my_user/folder3/myfile.dat,/Users/my_user/folder1/otherfile.dat
.
.
.
so on

到目前為止，我已經嘗試過一個循環：

with open("test.txt", "a") as myfile:
    myfile.write("append text")

但是我只寫在文件的末尾。

Answer 1

您可以使用re.sub函數。

在每行的開頭附加。

with open("test.txt", "r") as myfile:
    fil = myfile.read().rstrip('\n')
with open("test.txt", "w") as f:
    f.write(re.sub(r'(?m)^', r'append text', fil))

在每行末尾附加。

with open("test.txt", "r") as myfile:
    fil = myfile.read().rstrip('\n')
with open("test.txt", "w") as f:
    f.write(re.sub(r'(?m)$', r'append text', fil))

Answer 2

您可以嘗試執行以下操作：

with open(file_name, 'r') as f:
    file_lines = [''.join([x.strip(), string_to_add, '\n']) for x in f.readlines()]

with open(file_name, 'w') as f:
    f.writelines(file_lines)