在web登录中使用验证码，本质是在前端的img标签的src属性，动态传一张验证码图片。而动态使用验证码功能，则需使用pillow模块来动态生成验证码。

验证码本质

# 前端
<img src="/check_code/" style="width: 120px; height: 30px;">

# url
url(r'^check_code/', views.check_code),

# 后端
def check_code(request):
    f = open("static/1.jpg","rb")
    data = f.read()
    f.close()
    return HttpResponse(data)

pillow模块使用

def check_code(request):
    from PIL import Image,ImageDraw,ImageFont
    # 创建一张图片对象
    img = Image.new(mode="RGB", size=(120, 30), color=(0,255,0))

    # 创建一个画笔对象
    draw = ImageDraw.Draw(img, mode="RGB")

    # 生成随机字符串
    check_str = "".join([chr(random.randint(65,90)) for i in range(5)])

    # 写入随机字符串
    draw.text([0,0], check_str, "black",)

    # 存储到文件
    f = open("2.png", "wb")
    img.save(f, "png")
    f.close()
    # 返回到前端
    return HttpResponse(f1.read)

    # 存储到内存
    from io import BytesIO
    f1 = BytesIO()
    img.save(f1, "png")
    # 返回到前端
    return HttpResponse(f1.getvalue())

pillow生成验证码

封装图片验证码模块

import random
from PIL import ImageDraw,Image,ImageFont,ImageFilter
def check_code(width=120, height=30, char_length=5, font_file='kumo.ttf', font_size=28):
    """
    
    :param width: 生成图片宽度(int)
    :param height:生成图片高度(int)
    :param char_length: 验证码长度(int)
    :param font_file:  字体文件(file_path)
    :param font_size: 字体大小(int)
    :return: (img,str)图片对象 和 验证码字符串
    """
    code = []
    img = Image.new(mode='RGB', size=(width, height), color=(255, 255, 255))
    draw = ImageDraw.Draw(img, mode='RGB')

    def rndChar():
        """
        生成随机字母
        :return:
        """
        return chr(random.randint(65, 90))

    def rndColor():
        """
        生成随机颜色
        :return:
        """
        return (random.randint(0, 255), random.randint(10, 255), random.randint(64, 255))

    # 写文字
    font = ImageFont.truetype(font_file, font_size)
    for i in range(char_length):
        char = rndChar()
        code.append(char)
        h = random.randint(0, 4)
        draw.text([i * width / char_length, h], char, font=font, fill=rndColor())

    # 写干扰点
    for i in range(40):
        draw.point([random.randint(0, width), random.randint(0, height)], fill=rndColor())

    # 写干扰圆圈
    for i in range(40):
        draw.point([random.randint(0, width), random.randint(0, height)], fill=rndColor())
        x = random.randint(0, width)
        y = random.randint(0, height)
        draw.arc((x, y, x + 4, y + 4), 0, 90, fill=rndColor())

    # 画干扰线
    for i in range(5):
        x1 = random.randint(0, width)
        y1 = random.randint(0, height)
        x2 = random.randint(0, width)
        y2 = random.randint(0, height)

        draw.line((x1, y1, x2, y2), fill=rndColor())

    img = img.filter(ImageFilter.EDGE_ENHANCE_MORE)
    return img, ''.join(code)

图片验证码示例

def check_code(request):
    # 内存读写模块
    from io import BytesIO
    # 自定义验证码模块
    from utils import random_check_code
    img,check_str = random_check_code.check_code(120,30,5,"utils/domi.ttf",28)
    stream = BytesIO()
    img.save(stream,"png")
    request.session["check_str"]=check_str
    return HttpResponse(stream.getvalue())

参考博客