**there is my code**

class Solution(object):

def combinationSum4(self, nums, target):

"""

:type nums: List[int]

:type target: int

:rtype: int

"""

if target==0:

return 1

elif target<0:

return 0

else:

sum=0

for i in nums:

sum=sum+combinationSum4(self,nums,target-i)

return sum

**Line 15: NameError: global name 'combinationSum4' is not defined**

I don't know the reason,I hope you can help me.Thank you very much!