#验证码
@api.route('/imgCode')
def imgCode():
  return imageCode().getImgCode()

def geneText():
  '''生成4位验证码'''
  return ''.join(random.sample(string.ascii_letters + string.digits, 4)) #ascii_letters是生成所有字母 digits是生成所有数字0-9

def rndColor():
  '''随机颜色'''
  return (random.randint(32, 127), random.randint(32, 127), random.randint(32, 127))

def getVerifyCode():
  '''生成验证码图形'''
  code = geneText()
  # 图片大小120×50
  width, height = 120, 50
  # 新图片对象
  im = Image.new('RGB', (width, height), 'white')
  # 字体
  font = ImageFont.truetype('app/static/arial.ttf', 40)
  # draw对象
  draw = ImageDraw.Draw(im)
  # 绘制字符串
  for item in range(4):
    draw.text((5 + random.randint(-3, 3) + 23 * item, 5 + random.randint(-3, 3)),
         text=code[item], fill=rndColor(), font=font)
  return im, code

def getImgCode():
  image, code = getVerifyCode()
  # 图片以二进制形式写入
  buf = BytesIO()
  image.save(buf, 'jpeg')
  buf_str = buf.getvalue()
  # 把buf_str作为response返回前端，并设置首部字段
  response = make_response(buf_str)
  response.headers['Content-Type'] = 'image/gif'
  # 将验证码字符串储存在session中
  session['imageCode'] = code
  return response

def drawLines(draw, num, width, height):
  '''划线'''
  for num in range(num):
    x1 = random.randint(0, width / 2)
    y1 = random.randint(0, height / 2)
    x2 = random.randint(0, width)
    y2 = random.randint(height / 2, height)
    draw.line(((x1, y1), (x2, y2)), fill='black', width=1)

def getVerifyCode():
  '''生成验证码图形'''
  code = geneText()
  # 图片大小120×50
  width, height = 120, 50
  # 新图片对象
  im = Image.new('RGB', (width, height), 'white')
  # 字体
  font = ImageFont.truetype('app/static/arial.ttf', 40)
  # draw对象
  draw = ImageDraw.Draw(im)
  # 绘制字符串
  for item in range(4):
    draw.text((5 + random.randint(-3, 3) + 23 * item, 5 + random.randint(-3, 3)),
         text=code[item], fill=rndColor(), font=font)
  # 划线
  drawLines(draw, 2, width, height)
  return im, code

from .. import *
from io import BytesIO
import random
import string
from PIL import Image, ImageFont, ImageDraw, ImageFilter
#验证码
@api.route('/imgCode')
def imgCode():
  return imageCode().getImgCode()
class imageCode():
  '''
  验证码处理
  '''
  def rndColor(self):
    '''随机颜色'''
    return (random.randint(32, 127), random.randint(32, 127), random.randint(32, 127))
  def geneText(self):
    '''生成4位验证码'''
    return ''.join(random.sample(string.ascii_letters + string.digits, 4)) #ascii_letters是生成所有字母 digits是生成所有数字0-9
  def drawLines(self, draw, num, width, height):
    '''划线'''
    for num in range(num):
      x1 = random.randint(0, width / 2)
      y1 = random.randint(0, height / 2)
      x2 = random.randint(0, width)
      y2 = random.randint(height / 2, height)
      draw.line(((x1, y1), (x2, y2)), fill='black', width=1)
  def getVerifyCode(self):
    '''生成验证码图形'''
    code = self.geneText()
    # 图片大小120×50
    width, height = 120, 50
    # 新图片对象
    im = Image.new('RGB', (width, height), 'white')
    # 字体
    font = ImageFont.truetype('app/static/arial.ttf', 40)
    # draw对象
    draw = ImageDraw.Draw(im)
    # 绘制字符串
    for item in range(4):
      draw.text((5 + random.randint(-3, 3) + 23 * item, 5 + random.randint(-3, 3)),
           text=code[item], fill=self.rndColor(), font=font)
    # 划线
    self.drawLines(draw, 2, width, height)
    return im, code
  def getImgCode(self):
    image, code = self.getVerifyCode()
    # 图片以二进制形式写入
    buf = BytesIO()
    image.save(buf, 'jpeg')
    buf_str = buf.getvalue()
    # 把buf_str作为response返回前端，并设置首部字段
    response = make_response(buf_str)
    response.headers['Content-Type'] = 'image/gif'
    # 将验证码字符串储存在session中
    session['imageCode'] = code
    return response

<div class="layui-form-item">
  <label class="layui-icon layui-icon-vercode" for="captcha"></label>
  <input type="text" name="captcha" lay-verify="required|captcha" placeholder="图形验证码" autocomplete="off"
      class="layui-input verification captcha" value="">
  <div class="captcha-img">
    <img id="verify_code" class="verify_code" src="/UploadFiles/2021-04-08/imgCode">

js：主要是针对验证失败以后，刷新图片验证码



// 进行登录操作
      form.on('submit(login)', function (data) {
        console.log(data.elem);
        var form_data = data.field;
        //加密成md5
        form_data.password=$.md5(form_data.password);
        $.ajax({
          url: "{{ url_for('api.api_login') }}",
          data: form_data,
          dataType: 'json',
          type: 'post',
          success: function (data) {
            if (data['code'] == 0) {
              location.href = "{{ url_for('home.homes') }}";
            } else {
              //登录失败则刷新图片验证码
              var tagImg = document.getElementById('verify_code');
              tagImg.src='/api/imgCode"htmlcode">

if request.method == 'POST':
  username = request.form.get('username')
  password = request.form.get('password')
  captcha = request.form.get('captcha').lower()




　　2）对验证码进行验证.因为我们在生成验证码的时候，就已经把验证码保存到session中，这里直接取当时生成的验证码，然后跟前端传过来的值对比即可。


 if captcha==session['imageCode'].lower():
   pass
 else：
   return jsonify({'code':-1,'msg':'图片验证码错误'})


到此，已完成了获取验证码、显示验证码、验证验证码的所有流程。验证验证码中没有把整体代码写出来。可以根据自己情况自己写。
总结
以上所述是小编给大家介绍的flask实现验证码并验证功能，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！

如果你觉得本文对你有帮助，欢迎转载，烦请注明出处，谢谢！