我如何在Python中指明字符串中的换行符,以便我可以将多行写入文本文件?


当前回答

您可以单独写入新行,也可以在单个字符串中写入,这样更容易。

示例1

输入

line1 = "hello how are you"
line2 = "I am testing the new line escape sequence"
line3 = "this seems to work"

你可以把“\n”分开写:

file.write(line1)
file.write("\n")
file.write(line2)
file.write("\n")
file.write(line3)
file.write("\n")

输出

hello how are you
I am testing the new line escape sequence
this seems to work

示例2

输入

正如其他人在之前的回答中指出的那样,将\n放在字符串中的相关点:

line = "hello how are you\nI am testing the new line escape sequence\nthis seems to work"

file.write(line)

输出

hello how are you
I am testing the new line escape sequence
this seems to work

其他回答

这取决于你想要多正确。\n通常会做这项工作。如果你真的想要正确,你可以在os包中查找换行符。(这实际上叫做linesep。)

注意:当使用Python API写入文件时,不要使用os.linesep。只使用\n;Python会自动将其转换为适合您平台的换行符。

各种等效方法

使用打印

默认情况下,打印已经追加了换行符!

with open("out.txt", "w") as f:
    print("First", file=f)
    print("Second", file=f)

等同于:

with open("out.txt", "w") as f:
    print("First\nSecond", file=f)

要打印而不自动添加换行符,使用sep=""(因为sep="\n"是默认值):

with open("out.txt", "w") as f:
    print("First\nSecond\n", sep="", file=f)

使用f.write

对于以文本模式打开的文件:

with open("out.txt", "w") as f:
    f.write("First\nSecond\n")

对于以二进制模式打开的文件,写入文件时不会自动将\n转换为特定于平台的行结束符。要强制使用当前平台的换行符,请使用os。Linesep代替\n:

with open("out.txt", "wb") as f:
    f.write("First" + os.linesep)
    f.write("Second" + os.linesep)

输出文件

视觉:

First
Second

在Linux上,换行符将以\n分隔:

First\nSecond\n

在Windows中,换行符将以\r\n分隔:

First\r\nSecond\r\n

为了避免以文本模式打开的文件自动将\n转换为\r\n,请使用open("out.txt", "w", newline="\n")打开文件。

新的行字符是\n。它用于字符串内部。

例子:

    print('First line \n Second line') 

其中\n是换行符。

这将产生如下结果:

First line
 Second line

如果使用Python 2,则不对打印函数使用圆括号。

Use:

"{}\n{}\n{}".format(
    "line1",
    "line2",
    "line3"
)

我个人更喜欢这种形式。

\n -简单换行符插入工作:

# Here's the test example - string with newline char:
In [36]: test_line = "Hi!!!\n testing first line.. \n testing second line.. \n and third line....."

输出:

In [37]: print(test_line)

Hi!!!
 testing first line..
 testing second line..
 and third line.....