Python随机验证码生成和join 字符串的问题解析

#对序列进行操作（分别使用' '与':'作为分隔符）
  
>>> seq1 = ['hello','Good','boy','doiido']

>>> print ' '.join(seq1)
hello good boy doiido
>>> print ':'.join(seq1)
hello:good:boy:doiido
    
#对字符串进行操作
>>> seq2 = "hello good boy doiido"
>>> print ':'.join(seq2)
h:e:l:l:o: :g:o:o:d: :b:o:y: :d:o:i:i:d:o
#对元组进行操作  
>>> seq3 = ('hello','good','boy','doiido')
>>> print ':'.join(seq3)
#对字典进行操作
>>> seq4 = {'hello':1,'good':2,'boy':3,'doiido':4}
>>> print ':'.join(seq4)
boy:good:doiido:hello
#合并目录  
>>> import os
>>> os.path.join('/hello/','good/boy/','doiido')
'/hello/good/boy/doiido'

import random
li = []
for i  in range(6):
    r = random.randrange(0,5)
    print(r)
    if r == 2 or r ==4:
        num = random.randrange(0,10)
        li.append(str(num))
    else:
        tmp = random.randrange(65,91)
        c = chr(tmp)
        li.append(c)

    
print(li)
re = "".join(li)    
print(re)

import random,string
#方法1
li_code = []
for i in range(65,91):#大写字母A-Z
    li_code.append(chr(i))
for j in range(97,123):#小写字母a-z
    li_code.append(chr(j))
for k in range(48,58):#数字0-9
    li_code.append(chr(k))
code = random.sample(li_code,6)
ran_code = "".join(code)
print(ran_code)

import random,string
#方法2
str1 = "0123456789"
str2 = string.ascii_letters
str3 = str1+str2
code = random.sample(str3,6)
l_code = "".join(code)
print(l_code)

import random,string
#方法3
s_code = string.ascii_letters+string.digits
code = random.sample(s_code,6)
print("".join(code))