Python的Django框架完成一个完整的论坛（4.项目…

"""
制造验证码
"""
import random
from PIL import Image, ImageDraw, ImageFont, ImageFilter

_letter_cases = "abcdefghjkmnpqrstuvwxy"  # 小写字母，去除可能干扰的i，l，o，z
_upper_cases = _letter_cases.upper()  # 大写字母
_numbers = ''.join(map(str, range(3, 10)))  # 数字
init_chars = ''.join((_letter_cases, _upper_cases, _numbers))


def create_validate_code(size=(120, 30),
                         chars=init_chars,
                         img_type="GIF",
                         mode="RGB",
                         bg_color=(255, 255, 255),
                         fg_color=(0, 0, 255),
                         font_size=18,
                         font_type="Monaco.ttf",
                         length=4,
                         draw_lines=True,
                         n_line=(1, 2),
                         draw_points=True,
                         point_chance=2):
    """
    @todo: 生成验证码图片
    @param size: 图片的大小，格式（宽，高），默认为(120, 30)
    @param chars: 允许的字符集合，格式字符串
    @param img_type: 图片保存的格式，默认为GIF，可选的为GIF，JPEG，TIFF，PNG
    @param mode: 图片模式，默认为RGB
    @param bg_color: 背景颜色，默认为白色
    @param fg_color: 前景色，验证码字符颜色，默认为蓝色#0000FF
    @param font_size: 验证码字体大小
    @param font_type: 验证码字体，默认为 ae_AlArabiya.ttf
    @param length: 验证码字符个数
    @param draw_lines: 是否划干扰线
    @param n_lines: 干扰线的条数范围，格式元组，默认为(1, 2)，只有draw_lines为True时有效
    @param draw_points: 是否画干扰点
    @param point_chance: 干扰点出现的概率，大小范围[0, 100]
    @return: [0]: PIL Image实例
    @return: [1]: 验证码图片中的字符串
    """

    width, height = size  # 宽高
    # 创建图形
    img = Image.new(mode, size, bg_color)
    draw = ImageDraw.Draw(img)  # 创建画笔

    def get_chars():
        """生成给定长度的字符串，返回列表格式"""
        return random.sample(chars, length)

    def create_lines():
        """绘制干扰线"""
        line_num = random.randint(*n_line)  # 干扰线条数

        for i in range(line_num):
            # 起始点
            begin = (random.randint(0, size[0]), random.randint(0, size[1]))
            # 结束点
            end = (random.randint(0, size[0]), random.randint(0, size[1]))
            draw.line([begin, end], fill=(0, 0, 0))

    def create_points():
        """绘制干扰点"""
        chance = min(100, max(0, int(point_chance)))  # 大小限制在[0, 100]

        for w in range(width):
            for h in range(height):
                tmp = random.randint(0, 100)
                if tmp > 100 - chance:
                    draw.point((w, h), fill=(0, 0, 0))

    def create_strs():
        """绘制验证码字符"""
        c_chars = get_chars()
        strs = ' %s ' % ' '.join(c_chars)  # 每个字符前后以空格隔开

        font = ImageFont.truetype(font_type, font_size)
        font_width, font_height = font.getsize(strs)

        draw.text(((width - font_width) / 3, (height - font_height) / 3),
                  strs, font=font, fill=fg_color)

        return ''.join(c_chars)

    if draw_lines:
        create_lines()
    if draw_points:
        create_points()
    strs = create_strs()

    # 图形扭曲参数
    params = [1 - float(random.randint(1, 2)) / 100,
              0,
              0,
              0,
              1 - float(random.randint(1, 10)) / 100,
              float(random.randint(1, 2)) / 500,
              0.001,
              float(random.randint(1, 2)) / 500
              ]
    img = img.transform(size, Image.PERSPECTIVE, params)  # 创建扭曲

    img = img.filter(ImageFilter.EDGE_ENHANCE_MORE)  # 滤镜，边界加强（阈值更大）

    return img, strs

from django.utils.safestring import mark_safe


class Pagination(object):
    """
    分页
    """

    def __init__(self, current_page, data_count, per_page_count=10, pager_num=7):
        try:
            self.current_page = int(current_page)
        except Exception as e:
            self.current_page = 1
        self.data_count = data_count
        self.per_page_count = per_page_count
        self.pager_num = pager_num

    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page * self.per_page_count

    @property
    def total_count(self):
        v, y = divmod(self.data_count, self.per_page_count)
        if y:
            v += 1
        return v

    def page_str(self, base_url):
        page_list = []

        if self.total_count < self.pager_num:
            start_index = 1
            end_index = self.total_count + 1
        else:
            if self.current_page <= (self.pager_num + 1) / 2:
                start_index = 1
                end_index = self.pager_num + 1
            else:
                start_index = self.current_page - (self.pager_num - 1) / 2
                end_index = self.current_page + (self.pager_num + 1) / 2
                if (self.current_page + (self.pager_num - 1) / 2) > self.total_count:
                    end_index = self.total_count + 1
                    start_index = self.total_count - self.pager_num + 1

        if self.current_page == 1:
            prev = '<li><a class="page" href="javascript:void(0);">上一页</a></li>'
        else:
            prev = '<li><a class="page" href="%s?p=%s">上一页</a></li>' % (base_url, self.current_page - 1,)
        page_list.append(prev)

        for i in range(int(start_index), int(end_index)):
            if i == self.current_page:
                temp = '<li class="active"><a class="page active" href="%s?p=%s">%s</a></li>' % (base_url, i, i)
            else:
                temp = '<li><a class="page" href="%s?p=%s">%s</a></li>' % (base_url, i, i)
            page_list.append(temp)

        if self.current_page == self.total_count:
            nex = '<li><a class="page" href="javascript:void(0);">下一页</a></li>'
        else:
            nex = '<li><a class="page" href="%s?p=%s">下一页</a></li>' % (base_url, self.current_page + 1,)
        page_list.append(nex)
        page_str = mark_safe("".join(page_list))

        return page_str