Would you believe some people here claim China is not Communist?

I haven't kept up with it, but I thought (while they're still communist, they're no longer) pure communist, as they've moved a lot further away from it in some respects.

It has more to do with people being fed years of propaganda more then anything. I will point out though the GDR was a multi party nation so a single party is not a strict requirement.

From what I understand (I'm no China scholar) the government is communist, but they take a capitalist stance when it comes to the economy and trading.

In reality, it is rather closer to state-owned capitalism. But some people believe that to be communism. In the purist form, however, communism is stateless. The state-capitalist form is intended to be a temporary transitionary step. However, being a highly authoritarian phase and the corrupting influence of power means that these states usually get stuck in this spot. The hardest part of forming a communist state is when the state has to begin ceding power it obtained to defeat wealthy private interests. Most states that call themselves communist are more of an aspirational label that failed to be realized.

I mean, North Korea calls themselves a Democratic Republic. Do you actually believe that?

Economically they're a market economy now. That's why people say that.