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question

** Dashatize it **

Given a number, return a string with dash'-'marks before and after each odd integer, but do not begin or end the string with a dash mark.

Ex:

dashatize(274) -> '2-7-4'
dashatize(6815) -> '68-1-5'

solutions

my solutions

def dashatize(num):
    l2 = [ ]
    if num == None:
        return 'None'
    else:
         # 将字符串抓为数字存为数组l2
        l = list(str(num))
        for i in range(len(l)):
            if l[i] != '-':
                l[i] = int(l[i])
                l2.append(l[i])
        # 将分配字符和符号存为数组l3 
        l3 = [l2[0],]
        for  i in range(1, len(l2)):
            if l2[i] % 2 == 0 and l2[i-1] % 2 != 0:
                l3.append('-')
                l3.append(l2[i])
            elif l2[i] % 2 != 0:
                l3.append('-')
                l3.append(l2[i])
            else:
                l3.append(l2[i])  
        c = map(str,l3)
      
        return "".join(c)

other solutions

import re
def dashatize(num):
    try:
        return ''.join(['-'+i+'-' if int(i)%2 else i for i in str(abs(num))]).replace('--','-').strip('-')
    except:
        return 'None'

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