Python实现网站注册验证码生成类

# -*- coding:utf-8 -*-
'''
Created on 2017年4月7日

@author: Water
'''
import os
import random
import string
import sys
import math
from PIL import Image,ImageDraw,ImageFont,ImageFilter
from django.conf import settings

 
#字体的位置，不同版本的系统会有不同
font_path = os.path.join('/home/workspace/aofeiKart/static', 'fonts/monaco.ttf')#settings.STATIC_ROOT, 'fonts/MONACO.TTF')
font_path = os.path.join(settings.STATIC_ROOT, 'fonts/monaco.ttf')
# print font_path
#生成几位数的验证码
number = 4
#生成验证码图片的高度和宽度
size = (100,30)
#背景颜色，默认为白色
bgcolor = (255,255,255)
#字体颜色，默认为蓝色
fontcolor = (0,0,255)
#干扰线颜色。默认为红色
linecolor = (255,0,0)
#是否要加入干扰线
draw_line = True
#加入干扰线条数的上下限
line_number = (1,5)
 
#用来随机生成一个字符串
# source = list(string.ascii_lowercase+'1234567890')
source = list('1234567890')
def gene_text():
#     return '6666'
    return ''.join(random.sample(source,number))#number是生成验证码的位数
#用来绘制干扰线
def gene_line(draw,width,height):
    begin = (random.randint(0, width), random.randint(0, height))
    end = (random.randint(0, width), random.randint(0, height))
    draw.line([begin, end], fill = linecolor)
 
#生成验证码
def gene_code():
    width,height = size #宽和高
    image = Image.new('RGBA',(width,height),bgcolor) #创建图片
    font = ImageFont.truetype(font_path,25) #验证码的字体
    draw = ImageDraw.Draw(image)  #创建画笔
    text = gene_text() #生成字符串
    font_width, font_height = font.getsize(text)
    draw.text(((width - font_width) / number, (height - font_height)/number),text,
            font= font,fill=fontcolor) #填充字符串
    if draw_line:
        gene_line(draw,width,height)
    image = image.transform((width+20,height+10), Image.AFFINE, (1,-0.3,0,-0.1,1,0), Image.BILINEAR)  #创建扭曲
    image = image.filter(ImageFilter.EDGE_ENHANCE_MORE) #滤镜，边界加强
    image_file = text+'.png'
    
    image_path = os.path.join(settings.STATIC_ROOT, 'images/%s'%image_file)

    image.save(image_path) #保存验证码图片
    
    return 'http://login.*.net:8000/static/images/%s'%image_file, text

if __name__ == "__main__":
    print gene_code()

实现过程很简单，主要注意有2点：
1.安装PIL库，设置好字体保存目录

2.如果直接返回图片的二进制数据流的話，如下：

buf = io.BytesIO() #io.BytesIO() #io.StringIO() use it to fill str obj
image.save(buf, 'png')
request.session['captcha'] = text.lower() 

return HttpResponse(buf.getvalue(), 'image/png') # return the image data stream as image/jpeg format, browser will treat it as an image