Python中如何多行编写单行字符串且输出仍为单行

在Python里，有几种实用方法可以把长字符串拆成多行编写，同时保证最终赋值或打印结果为单行，完全符合PEP8的行长度要求：

方法1：利用Python字符串自动拼接特性（首推） #

Python会自动拼接相邻的字符串字面量，哪怕它们处于不同行。用圆括号包裹能让换行结构更清晰，完美契合PEP8格式：

print(
    "This is an extremely long string that is definitely much, much longer than "
    "any kind of PEP8 standard would allow because wow this is too long for one line, PEP8 is right."
)

这种方式无需额外运算符或转义符，代码整洁易读，输出结果就是完整的单行字符串。

方法2：使用+运算符显式拼接 #

如果需要明确体现拼接逻辑，可以用+运算符，建议把+放在行尾（符合PEP8换行风格）：

long_string = "This is an extremely long string that is definitely much, much longer than " +
              "any kind of PEP8 standard would allow because wow this is too long for one line, PEP8 is right."
print(long_string)

也可以用续行符\实现换行：

long_string = "This is an extremely long string that is definitely much, much longer than " \
              "any kind of PEP8 standard would allow because wow this is too long for one line, PEP8 is right."
print(long_string)

方法3：三重引号加反斜杠消除换行 #

若使用三重引号定义字符串，需在每行末尾添加\来抵消自动生成的换行符：

print("""This is an extremely long string that is definitely much, much longer than \
any kind of PEP8 standard would allow because wow this is too long for one line, PEP8 is right.""")

不过这种方式容易遗漏反斜杠，可靠性不如第一种方法。

内容的提问来源于stack exchange，提问作者Viru2008