一、图形验证码

1.依赖包安装

pip install pillow

2.图形验证码封装

import random
import string
import os.path
from io import BytesIO

from PIL import Image
from PIL import ImageFilter
from PIL.ImageDraw import Draw
from PIL.ImageFont import truetype


class Bezier:
    def __init__(self):
        self.tsequence = tuple([t / 20.0 for t in range(21)])
        self.beziers = {}

    def pascal_row(self, n):
        """ Returns n-th row of Pascal's triangle
        """
        result = [1]
        x, numerator = 1, n
        for denominator in range(1, n // 2 + 1):
            x *= numerator
            x /= denominator
            result.append(x)
            numerator -= 1
        if n & 1 == 0:
            result.extend(reversed(result[:-1]))
        else:
            result.extend(reversed(result))
        return result

    def make_bezier(self, n):
        """ Bezier curves:
            http://en.wikipedia.org/wiki/B%C3%A9zier_curve#Generalization
        """
        try:
            return self.beziers[n]
        except KeyError:
            combinations = self.pascal_row(n - 1)
            result = []
            for t in self.tsequence:
                tpowers = (t ** i for i in range(n))
                upowers = ((1 - t) ** i for i in range(n - 1, -1, -1))
                coefs = [c * a * b for c, a, b in zip(combinations,
                                                      tpowers, upowers)]
                result.append(coefs)
            self.beziers[n] = result
            return result


class Captcha(object):
    def __init__(self):
        self._bezier = Bezier()
        self._dir = os.path.dirname(__file__)
        # self._captcha_path = os.path.join(self._dir, '..', 'static', 'captcha')

    @staticmethod
    def instance():
        if not hasattr(Captcha, "_instance"):
            Captcha._instance = Captcha()
        return Captcha._instance

    def initialize(self, width=200, height=75, color=None, text=None, fonts=None):
        # self.image = Image.new('RGB', (width, height), (255, 255, 255))
        self._text = text if text else random.sample(string.ascii_uppercase + string.ascii_uppercase + '3456789', 4)
        self.fonts = fonts if fonts else \
            [os.path.join(self._dir, 'fonts', font) for font in ['Arial.ttf', 'Georgia.ttf', 'actionj.ttf']]
        self.width = width
        self.height = height
        self._color = color if color else self.random_color(0, 200, random.randint(220, 255))

    @staticmethod
    def random_color(start, end, opacity=None):
        red = random.randint(start, end)
        green = random.randint(start, end)
        blue = random.randint(start, end)
        if opacity is None:
            return red, green, blue
        return red, green, blue, opacity

    # draw image

    def background(self, image):
        Draw(image).rectangle([(0, 0), image.size], fill=self.random_color(238, 255))
        return image

    @staticmethod
    def smooth(image):
        return image.filter(ImageFilter.SMOOTH)

    def curve(self, image, width=4, number=6, color=None):
        dx, height = image.size
        dx /= number
        path = [(dx * i, random.randint(0, height))
                for i in range(1, number)]
        bcoefs = self._bezier.make_bezier(number - 1)
        points = []
        for coefs in bcoefs:
            points.append(tuple(sum([coef * p for coef, p in zip(coefs, ps)])
                                for ps in zip(*path)))
        Draw(image).line(points, fill=color if color else self._color, width=width)
        return image

    def noise(self, image, number=50, level=2, color=None):
        width, height = image.size
        dx = width / 10
        width -= dx
        dy = height / 10
        height -= dy
        draw = Draw(image)
        for i in range(number):
            x = int(random.uniform(dx, width))
            y = int(random.uniform(dy, height))
            draw.line(((x, y), (x + level, y)), fill=color if color else self._color, width=level)
        return image

    def text(self, image, fonts, font_sizes=None, drawings=None, squeeze_factor=0.75, color=None):
        color = color if color else self._color
        fonts = tuple([truetype(name, size)
                       for name in fonts
                       for size in font_sizes or (65, 70, 75)])
        draw = Draw(image)
        char_images = []
        for c in self._text:
            font = random.choice(fonts)
            c_width, c_height = draw.textsize(c, font=font)
            char_image = Image.new('RGB', (c_width, c_height), (0, 0, 0))
            char_draw = Draw(char_image)
            char_draw.text((0, 0), c, font=font, fill=color)
            char_image = char_image.crop(char_image.getbbox())
            for drawing in drawings:
                d = getattr(self, drawing)
                char_image = d(char_image)
            char_images.append(char_image)
        width, height = image.size
        offset = int((width - sum(int(i.size[0] * squeeze_factor)
                                  for i in char_images[:-1]) -
                      char_images[-1].size[0]) / 2)
        for char_image in char_images:
            c_width, c_height = char_image.size
            mask = char_image.convert('L').point(lambda i: i * 1.97)
            image.paste(char_image,
                        (offset, int((height - c_height) / 2)),
                        mask)
            offset += int(c_width * squeeze_factor)
        return image

    # draw text
    @staticmethod
    def warp(image, dx_factor=0.27, dy_factor=0.21):
        width, height = image.size
        dx = width * dx_factor
        dy = height * dy_factor
        x1 = int(random.uniform(-dx, dx))
        y1 = int(random.uniform(-dy, dy))
        x2 = int(random.uniform(-dx, dx))
        y2 = int(random.uniform(-dy, dy))
        image2 = Image.new('RGB',
                           (width + abs(x1) + abs(x2),
                            height + abs(y1) + abs(y2)))
        image2.paste(image, (abs(x1), abs(y1)))
        width2, height2 = image2.size
        return image2.transform(
            (width, height), Image.QUAD,
            (x1, y1,
             -x1, height2 - y2,
             width2 + x2, height2 + y2,
             width2 - x2, -y1))

    @staticmethod
    def offset(image, dx_factor=0.1, dy_factor=0.2):
        width, height = image.size
        dx = int(random.random() * width * dx_factor)
        dy = int(random.random() * height * dy_factor)
        image2 = Image.new('RGB', (width + dx, height + dy))
        image2.paste(image, (dx, dy))
        return image2

    @staticmethod
    def rotate(image, angle=25):
        return image.rotate(
            random.uniform(-angle, angle), Image.BILINEAR, expand=1)

    def captcha(self, path=None, fmt='JPEG'):
        """Create a captcha.

        Args:
            path: save path, default None.
            fmt: image format, PNG / JPEG.
        Returns:
            A tuple, (text, StringIO.value).
            For example:
                ('JGW9', '\x89PNG\r\n\x1a\n\x00\x00\x00\r...')

        """
        image = Image.new('RGB', (self.width, self.height), (255, 255, 255))
        image = self.background(image)
        image = self.text(image, self.fonts, drawings=['warp', 'rotate', 'offset'])
        image = self.curve(image)
        image = self.noise(image)
        image = self.smooth(image)
        text = "".join(self._text)
        out = BytesIO()
        image.save(out, format=fmt)
        return text, out.getvalue()

    def generate_captcha(self):
        self.initialize()
        return self.captcha("")

captcha = Captcha.instance()

if __name__ == '__main__':
    print(captcha.generate_captcha())

二、后端使用

# 常量
from app.verifications.constants import IMAGE_CODE_EXPIRE_TIME,SMS_CODE_EXPIRE_TIME
# 生成图片验证码
from libs.captcha.captcha import captcha
# 导入redis
from django_redis import get_redis_connection
# 生成图片验证码
class ImageCodeView(View):

    def get(self,request,uuid):
        # 1.生成图片验证码和获取图片验证码的内容
        text,image = captcha.generate_captcha()
        # 2.1连接redis
        redis_conn = get_redis_connection('code')
        # 2.2将 图片验证码保存起来 uuid:xxxx 有有效期
        redis_conn.setex('img_%s'%uuid,IMAGE_CODE_EXPIRE_TIME,text)
        # 3.返回图片验证码
        return http.HttpResponse(image,content_type='image/jpeg')

备注：具体的前端请求图片上篇已经给出