Question

我创建了一个函数，可以生成一个连续递增的字母列表。 A，B，C ......，Z.在Z之后，它转到AA，AB，AC ...... AZ。这种模式重复。这类似于MS Excel的列名。目前，此函数生成一个有限的字母表列表。

_column_name_generator() = ['A', 'B', ..., 'AA', 'AB', ..., 'BA', 'BB', ..., 'CV']

然后我可以结合一些有限列表迭代它，例如0-10。请参阅下面的代码。我想要的是创建一个生成器，它将为我提供一个无限长的递增字母表列表。

import string


def _column_name_generator():
    column_names = []
    for x in range(0, 100):
        if x < 26:
            column_names.append(string.ascii_uppercase[x % 26])
        else:
            column_names.append(column_names[x/26 - 1] + string.ascii_uppercase[x % 26])
    return column_names

container = []
for column_name, num in zip(_column_name_generator(), range(0, 10)):
    container.append(column_name + str(num))

print _column_name_generator()
print container

container = ['A0', 'B1', 'C2', 'D3', 'E4', 'F5', 'G6', 'H7', 'I8', 'J9']

Answer 1

每次收益column_names的最后一个元素，并使用itertools.count代替range来提供无限增加：

import itertools

def _column_name_generator():
    column_names = []
    for x in itertools.count():
        if x < 26:
            column_names.append(string.ascii_uppercase[x % 26])
        else:
            column_names.append(column_names[x/26 - 1] + string.ascii_uppercase[x % 26])
        yield column_names[-1]

更好的解决方案，改变原始代码但忽略了column_names内存消耗列表中的需求，将是

import itertools, string

def _column_name_generator():
    for i in itertools.count(1):
        for p in itertools.product(string.ascii_uppercase, repeat=i):
            yield ''.join(p)

从i开始1 A B时，它基本上遍历长度为C的大写ascii字母（每个可能的序列）的乘积，<?php class WpProQuiz_Controller_Toplist extends WpProQuiz_Controller_Controller { public function route() { $quizId = $_GET['id']; $action = isset($_GET['action']) ? $_GET['action'] : 'show'; switch ($action) { default: $this->showAdminToplist($quizId); break; } } private function showAdminToplist($quizId) { if (!current_user_can('wpProQuiz_toplist_edit')) { wp_die(__('You do not have sufficient permissions to access this page.')); } $view = new WpProQuiz_View_AdminToplist(); $quizMapper = new WpProQuiz_Model_QuizMapper(); $quiz = $quizMapper->fetch($quizId); $view->quiz = $quiz; $view->show(); } public function getAddToplist(WpProQuiz_Model_Quiz $quiz) { $userId = get_current_user_id(); if (!$quiz->isToplistActivated()) { return null; } $data = array( 'userId' => $userId, 'token' => wp_create_nonce('wpProQuiz_toplist'), 'canAdd' => $this->preCheck($quiz->getToplistDataAddPermissions(), $userId), ); if ($quiz->isToplistDataCaptcha() && $userId == 0) { $captcha = WpProQuiz_Helper_Captcha::getInstance(); if ($captcha->isSupported()) { $data['captcha']['img'] = WPPROQUIZ_CAPTCHA_URL . '/' . $captcha->createImage(); $data['captcha']['code'] = $captcha->getPrefix(); } } return $data; } private function handleAddInToplist(WpProQuiz_Model_Quiz $quiz) { if (!wp_verify_nonce($this->_post['token'], 'wpProQuiz_toplist')) { return array('text' => __('An error has occurred.', 'wp-pro-quiz'), 'clear' => true); } if (!isset($this->_post['points']) || !isset($this->_post['totalPoints'])) { return array('text' => __('An error has occurred.', 'wp-pro-quiz'), 'clear' => true); } $quizId = $quiz->getId(); $userId = get_current_user_id(); $points = (int)$this->_post['points']; $totalPoints = (int)$this->_post['totalPoints']; $name = !empty($this->_post['name']) ? trim($this->_post['name']) : ''; $email = !empty($this->_post['email']) ? trim($this->_post['email']) : ''; $ip = filter_var($_SERVER['REMOTE_ADDR'], FILTER_VALIDATE_IP); $captchaAnswer = !empty($this->_post['captcha']) ? trim($this->_post['captcha']) : ''; $prefix = !empty($this->_post['prefix']) ? trim($this->_post['prefix']) : ''; $quizMapper = new WpProQuiz_Model_QuizMapper(); $toplistMapper = new WpProQuiz_Model_ToplistMapper(); if ($quiz == null || $quiz->getId() == 0 || !$quiz->isToplistActivated()) { return array('text' => __('An error has occurred.', 'wp-pro-quiz'), 'clear' => true); } if (!$this->preCheck($quiz->getToplistDataAddPermissions(), $userId)) { return array('text' => __('An error has occurred.', 'wp-pro-quiz'), 'clear' => true); } $numPoints = $quizMapper->sumQuestionPoints($quizId); if ($totalPoints > $numPoints || $points > $numPoints) { return array('text' => __('An error has occurred.', 'wp-pro-quiz'), 'clear' => true); } $clearTime = null; if ($quiz->isToplistDataAddMultiple()) { $clearTime = $quiz->getToplistDataAddBlock() * 60; } if ($userId > 0) { if ($toplistMapper->countUser($quizId, $userId, $clearTime)) { return array('text' => __('You can not enter again.', 'wp-pro-quiz'), 'clear' => true); } $user = wp_get_current_user(); $email = $user->user_email; $name = $user->display_name; } else { if ($toplistMapper->countFree($quizId, $name, $email, $ip, $clearTime)) { return array('text' => __('You can not enter again.', 'wp-pro-quiz'), 'clear' => true); } if (empty($name) || empty($email) || filter_var($email, FILTER_VALIDATE_EMAIL) === false) { return array('text' => __('No name or e-mail entered.', 'wp-pro-quiz'), 'clear' => false); } if (strlen($name) > 15) { return array('text' => __('Your name can not exceed 15 characters.', 'wp-pro-quiz'), 'clear' => false); } if ($quiz->isToplistDataCaptcha()) { $captcha = WpProQuiz_Helper_Captcha::getInstance(); if ($captcha->isSupported()) { if (!$captcha->check($prefix, $captchaAnswer)) { return array('text' => __('You entered wrong captcha code.', 'wp-pro-quiz'), 'clear' => false); } } } } $toplist = new WpProQuiz_Model_Toplist(); $toplist->setQuizId($quizId) ->setUserId($userId) ->setDate(time()) ->setName($name) ->setEmail($email) ->setPoints($points) ->setResult(round($points / $totalPoints * 100, 2)) ->setIp($ip); $toplistMapper->save($toplist); return true; } private function preCheck($type, $userId) { switch ($type) { case WpProQuiz_Model_Quiz::QUIZ_TOPLIST_TYPE_ALL: return true; case WpProQuiz_Model_Quiz::QUIZ_TOPLIST_TYPE_ONLY_ANONYM: return $userId == 0; case WpProQuiz_Model_Quiz::QUIZ_TOPLIST_TYPE_ONLY_USER: return $userId > 0; } return false; } public static function ajaxAdminToplist($data) { if (!current_user_can('wpProQuiz_toplist_edit')) { return json_encode(array()); } $toplistMapper = new WpProQuiz_Model_ToplistMapper(); $j = array('data' => array()); $limit = (int)$data['limit']; $start = $limit * ($data['page'] - 1); $isNav = isset($data['nav']); $quizId = $data['quizId']; if (isset($data['a'])) { switch ($data['a']) { case 'deleteAll': $toplistMapper->delete($quizId); break; case 'delete': if (!empty($data['toplistIds'])) { $toplistMapper->delete($quizId, $data['toplistIds']); } break; } $start = 0; $isNav = true; } $toplist = $toplistMapper->fetch($quizId, $limit, $data['sort'], $start); foreach ($toplist as $tp) { $j['data'][] = array( 'id' => $tp->getToplistId(), 'name' => $tp->getName(), 'email' => $tp->getEmail(), 'type' => $tp->getUserId() ? 'R' : 'UR', 'date' => WpProQuiz_Helper_Until::convertTime($tp->getDate(), get_option('wpProQuiz_toplistDataFormat', 'Y/m/d g:i A')), 'points' => $tp->getPoints(), 'result' => $tp->getResult() ); } if ($isNav) { $count = $toplistMapper->count($quizId); $pages = ceil($count / $limit); $j['nav'] = array( 'count' => $count, 'pages' => $pages ? $pages : 1 ); } return json_encode($j); } public static function ajaxAddInToplist($data) { // workaround ... $_POST = $_POST['data']; $ctn = new WpProQuiz_Controller_Toplist(); $quizId = isset($data['quizId']) ? $data['quizId'] : 0; $prefix = !empty($data['prefix']) ? trim($data['prefix']) : ''; $quizMapper = new WpProQuiz_Model_QuizMapper(); $quiz = $quizMapper->fetch($quizId); $r = $ctn->handleAddInToplist($quiz); if ($quiz->isToplistActivated() && $quiz->isToplistDataCaptcha() && get_current_user_id() == 0) { $captcha = WpProQuiz_Helper_Captcha::getInstance(); if ($captcha->isSupported()) { $captcha->remove($prefix); $captcha->cleanup(); if ($r !== true) { $r['captcha']['img'] = WPPROQUIZ_CAPTCHA_URL . '/' . $captcha->createImage(); $r['captcha']['code'] = $captcha->getPrefix(); } } } if ($r === true) { $r = array('text' => __('You signed up successfully.', 'wp-pro-quiz'), 'clear' => true); } return json_encode($r); } public static function ajaxShowFrontToplist($data) { // workaround ... $_POST = $_POST['data']; $quizIds = empty($data['quizIds']) ? array() : array_unique((array)$data['quizIds']); $toplistMapper = new WpProQuiz_Model_ToplistMapper(); $quizMapper = new WpProQuiz_Model_QuizMapper(); $j = array(); foreach ($quizIds as $quizId) { $quiz = $quizMapper->fetch($quizId); if ($quiz == null || $quiz->getId() == 0) { continue; } $toplist = $toplistMapper->fetch($quizId, $quiz->getToplistDataShowLimit(), $quiz->getToplistDataSort()); foreach ($toplist as $tp) { $j[$quizId][] = array( 'name' => $tp->getName(), 'date' => WpProQuiz_Helper_Until::convertTime($tp->getDate(), get_option('wpProQuiz_toplistDataFormat', 'Y/m/d g:i A')), 'points' => $tp->getPoints(), 'result' => $tp->getResult() ); } } return json_encode($j); } }）。

Answer 2

一种不那么pythonic的方式

正如你的问题所暗示的那样，一种方法是除以26将每个步骤的余数转换成一个字母，直到除法返回0.使用%（modulo）得到余数，// （楼层划分）更新下一步的值。这可能是代码：

numberOfElements = 100
letters = []
for counter in range(numberOfElements):
    i = counter
    newCharacter = i % 26
    i //= 26
    s = "" +chr(newCharacter + ord('A') )
    while i != 0:
        newCharacter = i % 26
        i //= 26
        s = chr(newCharacter + ord('A') ) + s
    letters.append(s)
print letters

结果：

['A'，'B'，'C'，'D'，'E'，'F'，'G'，'H'，'I'，'J'，'K'，'L '，'M'，'N'， 'O'，'P'，'Q'，'R'，'S'，'T'，'U'，'V'，'W'，'X'，'Y'，'Z'，'BA ”， 'BB'，'BC'，'BD'，'BE'，'BF'，'BG'，'BH'，'BI'，'BJ'，'BK'，'BL'， 'BM'，'BN'，'BO'，'BP'，'BQ'，'BR'，'BS'，'BT'，'BU'，'BV'，'BW'， 'BX'，'BY'，'BZ'，'CA'，'CB'，'CC'，'CD'，'CE'，'CF'，'CG'，'CH'， 'CI'，'CJ'，'CK'，'CL'，'CM'，'CN'，'CO'，'CP'，'CQ'，'CR'，'CS'， 'CT'，'CU'，'CV'，'CW'，'CX'，'CY'，'CZ'，'DA'，'DB'，'DC'，'DD'， 'DE'，'DF'，'DG'，'DH'，'DI'，'DJ'，'DK'，'DL'，'DM'，'DN'，'DO'， 'DP'，'DQ'，'DR'，'DS'，'DT'，'DU'，'DV']

如何创建一个无限迭代器来生成递增的字母模式？

2 个答案: