# -*- coding:utf-8 -*-
from PIL import Image, ImageDraw, ImageFont
import random, StringIO
import os
from math import ceil
import base64
current_path = os.path.normpath(os.path.dirname(__file__))
class Captcha(object):
# 定义一个验证码类，
def __init__(self, request):
self.django_request = request
self.session_key = request.session.session_key
self.words = []
# image size (pix)
self.img_width = 150
self.img_height = 30
# default type
self.type = 'number'
def _get_font_size(self):
""" 将图片高度的80%作为字体大小
"""
s1 = int(self.img_height * 0.8)
s2 = int(self.img_width / len(self.code))
return int(min((s1, s2)) + max((s1, s2)) * 0.05)
def _get_words(self):
""" The words list
"""
# 扩充单词列表
if self.words:
return set(self.words)
file_path = os.path.join(current_path, 'words.list')
f = open(file_path, 'r')
return set([line.replace('\n', '') for line in f.readlines()])
def _set_answer(self, answer):
""" 设置答案
"""
self.django_request.session[self.session_key] = str(answer)
def _yield_code(self):
""" 生成验证码数字,以及答案
"""
# 数字公式验证码
def number():
m, n = 1, 50
x = random.randrange(m, n)
y = random.randrange(m, n)
r = random.randrange(0, 2)
if r == 0:
code = "%s - %s = ?" % (x, y)
z = x - y
else:
code = "%s + %s = ?" % (x, y)
z = x + y
self._set_answer(z)
return code
fun = eval(self.type.lower())
return fun()
def display(self):
""" 把生成的验证码图片改成数据流返回
"""
# 字体颜色
self.font_color = ['black', 'darkblue', 'darkred']
# 背景颜色，随机生成
self.background = (random.randrange(230, 255), random.randrange(230, 255), random.randrange(230, 255))
# 字体
self.font_path = os.path.join(current_path, 'timesbi.ttf')
# self.font_path = os.path.join(current_path,'Menlo.ttc')
# 生成的验证码只做一次验证，就会清空
self.django_request.session[self.session_key] = ''
# 使用 PIL创建画布
im = Image.new('RGB', (self.img_width, self.img_height), self.background)
# 生成验证码
self.code = self._yield_code()
# 设置字体大小
self.font_size = self._get_font_size()
# 实例化一个绘图
draw = ImageDraw.Draw(im)
# 在画布绘图,写验证码
if self.type == 'word':
c = int(8 / len(self.code) * 3) or 3
elif self.type == 'number':
c = 4
for i in range(random.randrange(c - 2, c)):
line_color = (random.randrange(0, 255), random.randrange(0, 255), random.randrange(0, 255))
xy = (
random.randrange(0, int(self.img_width * 0.2)),
random.randrange(0, self.img_height),
random.randrange(3 * self.img_width / 4, self.img_width),
random.randrange(0, self.img_height)
)
draw.line(xy, fill=line_color, width=int(self.font_size * 0.1))
# draw.arc(xy,fill=line_color,width=int(self.font_size*0.1))
# draw.arc(xy,0,1400,fill=line_color)
# code part
j = int(self.font_size * 0.3)
k = int(self.font_size * 0.5)
x = random.randrange(j, k) # starts point
for i in self.code:
# 上下抖动量,字数越多,上下抖动越大
m = int(len(self.code))
y = random.randrange(1, 3)
if i in ('+', '=', '?'):
# 对计算符号等特殊字符放大处理
m = ceil(self.font_size * 0.8)
else:
# 字体大小变化量,字数越少,字体大小变化越多
m = random.randrange(0, int(45 / self.font_size) + int(self.font_size / 5))
self.font = ImageFont.truetype(self.font_path.replace('\\', '/'), self.font_size + int(ceil(m)))
draw.text((x, y), i, font=self.font, fill=random.choice(self.font_color))
x += self.font_size * 0.9
del x
del draw
# 序列化处理
buf = StringIO.StringIO()
im.save(buf, 'gif')
buf.closed
data = base64.encodestring(buf.getvalue())
return data
def validate(self, code):
"""
检查用户输入和服务器上的密码是否一致
"""
if not code:
return False
_code = self.django_request.session.get(self.session_key) or ''
self.django_request.session[self.session_key] = ''
return _code.lower() == str(code).lower()
def check(self, code):
"""
检查用户输入和服务器上保存的密码是否一致
"""
return self.validate(code)
