class Solution:
def convertToBase7(self, num):
result = [] # 建立一个列表存放各七进制位
positive = True # 符号初始化
if num == 0:
return ‘0‘
elif num < 0:
positive = False
num = abs(num)
while num // 7 != 0 or num % 7 != 0: # 求七进制算法
result.append(num % 7)
num //= 7
if not positive:
result.append(‘-‘)
result.reverse()
return "".join(‘%s‘ %id for id in result) # 列表转换字符串，注意如果列表中有数字要先用for循环遍历列表再转换
