在python中包装行：打破参数字符串

Question

我有一个脚本，其中一个非常长的str类型的参数传递给一个函数：

parser = argparse.ArgumentParser(description='Auto-segments a text based on the TANGO algorithm (Rie Kubota Ando and Lillian Lee, "Mostly-Unsupervised Statistical Segmentation of Japanese Kanji Sequences" (Natural Language Engineering, 9(2):127-149, 2003)).')

我想将此脚本中的行长度限制为79个字符，这意味着在相关字符串的中间断行。简单地在79处包装产生类似这样的东西，这在语法上是不正确的：

parser = argparse.ArgumentParser(description="Auto-segments a text based on 
    the TANGO algorithm (Rie Kubota Ando and Lillian Lee, 'Mostly-Unsupervis
    ed Statistical Segmentation of Japanese Kanji Sequences' (Natural Langua
    ge Engineering, 9(2):127-149, 2003)).")

PEP 8有关于在各种非参数字符串内部位置中断行的指南，但有没有办法在参数字符串的中间打破这一行？

（相关但不太重要的问题：什么是在（python）脚本中打破自然语言文本中间词的明智/传统方式？）

Answer 1

文字字符串可以彼此相邻，并将编译为单个字符串。从而：

parser = argparse.ArgumentParser(description="Auto-segments a text based on "
    "the TANGO algorithm (Rie Kubota Ando and Lillian Lee, 'Mostly-Unsupervised "
    "Statistical Segmentation of Japanese Kanji Sequences' (Natural Language "
    "Engineering, 9(2):127-149, 2003)).")

根据需要调整以适应80。

Answer 2

>>>longarg = "ABCDEF\
GHIJKLMNOPQRSTUVW\
XYZ"

>>>print longarg
ABCDEFGHIJKLMNOPQRSTUVWXYZ

Answer 3

argparse无论如何重新格式化描述字符串，因此如果您使用带有额外空格的多行字符串，它将不会更改结果：

import argparse

parser = argparse.ArgumentParser(description='''Auto-segments a text based on the
    TANGO algorithm (Rie Kubota Ando and Lillian Lee, "Mostly-Unsupervised
    Statistical Segmentation of Japanese Kanji Sequences" (Natural Language
    Engineering, 9(2):127-149, 2003)).''')

args = parser.parse_args()

---

% test.py -h

usage: test.py [-h]

Auto-segments a text based on the TANGO algorithm (Rie Kubota Ando and Lillian Lee,
"Mostly-Unsupervised Statistical Segmentation of Japanese Kanji Sequences" (Natural
Language Engineering, 9(2):127-149, 2003)).

optional arguments:
  -h, --help  show this help message and exit