方法一：

利用range方法，对于range方法不清楚的同学，请参考文章《python开发的range()函数》

# -*- coding: utf-8 -*-
import random
def generate_verification_code(len=6):
 ''' 随机生成6位的验证码 '''
 # 注意： 这里我们生成的是0-9A-Za-z的列表，当然你也可以指定这个list，这里很灵活
 # 比如： code_list = ['P','y','t','h','o','n','T','a','b'] # PythonTab的字母
 code_list = [] 
 for i in range(10): # 0-9数字
 code_list.append(str(i))
 for i in range(65, 91): # 对应从“A”到“Z”的ASCII码
 code_list.append(chr(i))
 for i in range(97, 123): #对应从“a”到“z”的ASCII码
 code_list.append(chr(i))
 myslice = random.sample(code_list, len) # 从list中随机获取6个元素，作为一个片断返回
 verification_code = ''.join(myslice) # list to string
 return verification_code

方法二：

利用randint方法

# -*- coding: utf-8 -*-
import random
def generate_verification_code_v2():
 ''' 随机生成6位的验证码 '''
 code_list = []
 for i in range(2):
 random_num = random.randint(0, 9) # 随机生成0-9的数字
 # 利用random.randint()函数生成一个随机整数a，使得65<=a<=90
 # 对应从“A”到“Z”的ASCII码
 a = random.randint(65, 90)
 b = random.randint(97, 122)
 random_uppercase_letter = chr(a)
 random_lowercase_letter = chr(b)
 code_list.append(str(random_num))
 code_list.append(random_uppercase_letter)
 code_list.append(random_lowercase_letter)
 verification_code = ''.join(code_list)
 return verification_code

测试：

code = generate_verification_code(6)
code2 = generate_verification_code_v2()
print code
print code2

输出结果：

Glc5Tr
Hr6t7B

我个人更倾向于第一种方法，更加灵活，可以随意设置验证码长度。

Python 随机生成中文验证码

# -*- coding: utf-8 -*- 
import Image,ImageDraw,ImageFont 
import random 
import math, string 
class RandomChar(): 
 """用于随机生成汉字""" 
 @staticmethod 
 def Unicode(): 
 val = random.randint(0x4E00, 0x9FBF) 
 return unichr(val) 
 @staticmethod 
 def GB2312(): 
 head = random.randint(0xB0, 0xCF) 
 body = random.randint(0xA, 0xF) 
 tail = random.randint(0, 0xF) 
 val = ( head << 8 ) | (body << 4) | tail 
 str = "%x" % val 
 return str.decode('hex').decode('gb2312') 
class ImageChar(): 
 def __init__(self, fontColor = (0, 0, 0), 
 size = (100, 40), 
 fontPath = 'wqy.ttc', 
 bgColor = (255, 255, 255), 
 fontSize = 20): 
 self.size = size 
 self.fontPath = fontPath 
 self.bgColor = bgColor 
 self.fontSize = fontSize 
 self.fontColor = fontColor 
 self.font = ImageFont.truetype(self.fontPath, self.fontSize) 
 self.image = Image.new('RGB', size, bgColor) 
 def rotate(self): 
 self.image.rotate(random.randint(0, 30), expand=0) 
 def drawText(self, pos, txt, fill): 
 draw = ImageDraw.Draw(self.image) 
 draw.text(pos, txt, font=self.font, fill=fill) 
 del draw 
 def randRGB(self): 
 return (random.randint(0, 255), 
 random.randint(0, 255), 
 random.randint(0, 255)) 
 def randPoint(self): 
 (width, height) = self.size 
 return (random.randint(0, width), random.randint(0, height)) 
 def randLine(self, num): 
 draw = ImageDraw.Draw(self.image) 
 for i in range(0, num): 
 draw.line([self.randPoint(), self.randPoint()], self.randRGB()) 
 del draw 
 def randChinese(self, num): 
 gap = 5 
 start = 0 
 for i in range(0, num): 
 char = RandomChar().GB2312() 
 x = start + self.fontSize * i + random.randint(0, gap) + gap * i 
 self.drawText((x, random.randint(-5, 5)), RandomChar().GB2312(), self.randRGB()) 
 self.rotate() 
 self.randLine(18) 
 def save(self, path): 
 self.image.save(path)