Python 3 删除空列表

Question

我正在从 10 行的文本中找到一行。

desc    = re.findall(r'@description (.*)', comment.strip())

发生的是它返回 @description 但它也有 9 个空列表。

print(desc)

返回:

[]
[]
[]
[]
[]
[]
[]
[]
['the desc is here']
[]

那么如何摆脱那些空的 [] 并使 desc=['the desc is here']？

---

更新

我试过列表过滤器，结果还是一样

评论包含:

/**
 * @param string username   required    the username of the registering user 
 * @param string password   required
 * @param string first_name required
 * @param string last_name  required
 * @param string email      required
 * @package authentication
 * @info user registration
 * @description register a new user into the groupjump platform
 */

---

更新

comment是一个完整的字符串，所以我把它拆分成这样，这样我就可以逐行阅读

comments = route['comment']
comments = list(filter(None, comments.split('\n')))

---

实际代码

#!/usr/bin/env python3

import re

routes = []
description = ''
with open('troutes.php', 'r') as f:
    current_comment = ''
    in_comment = False
    for line in f:
        line = line.lstrip()
        if line.startswith('/**'):
            in_comment = True

        if in_comment:
            current_comment += line

        if line.startswith('*/'):
            in_comment = False

        if line.startswith('Route::'):
            matches = re.search(r"Route::([A-Z]+)\('(.*)', '(.*)'\);", line)
            groups = matches.groups()
            routes.append({
                'comment': current_comment,
                'method': groups[0],
                'path': groups[1],
                'handler': groups[2],
            });
            current_comment = '' # reset the comment

for route in routes:

  # get comments
  comments = route['comment']
  comments = list(filter(None, comments.split('\n')))

  for comment in comments:
    params  = re.findall(r'@param (.*)', comment.strip())
    object  = re.findall(r'@package (.*)', comment.strip())
    info    = re.findall(r'@info (.*)', comment.strip())
    desc    = re.search(r'@description (.*)', comment.strip())

    print(comment[15:])

正在读取的数据:

<?php
/**
 * @param string username   required    the username of the registering user 
 * @param string password   required
 * @param string first_name required
 * @param string last_name  required
 * @param string email      required
 * @package authentication
 * @info user registration
 * @description register a new user into the groupjump platform
 */
Route::POST('v3/register', 'UserController@Register');

/**
 * @param string username   required    the username of the registering user 
 * @param string password   required
 */
Route::GET('v3/login', 'UserController@login');

Answer 1

单个列表的条件是:

if desc:
    print(desc)

它是以下内容的简写版本:

if len(desc) > 0:
    print(desc)

对于列表的列表，它是:

desc = [d for d in desc if d]

要仅获取字符串，请执行以下操作:

if desc:
    print(desc[0])