I just want to get a prime number list, but I find that the for loops more times than I image, it seems that the sequence don't change even though I modified the variable with the same name.

I try name nums as global, but nothing changed.

```py
nums = list(range(2, 11))
count = 0
for num in nums:
    nums = list(filter(lambda a: a == num or a % num, nums))
    count += 1
print(count)  # 9
print(nums)

```

I want `nums = list...` can modify **nums** in `for num in nums`, and the count is 4.
Thank you.