global var declared but not using

Sorry for the late reply. It's Python's specifications.

def foo():
    import sys

foo()
sys # <- NameError occurs.

So, global vars are used.

I implement this code because

sympy is an optional requirement. So, blueqat should work without installing sympy
importing sympy is slow. In this implementation, sympy is imported when sympy backend is called in the first time and if sympy backend is not used, import sympy does not occur.

However, using many global vars is not a good implementation :( Thanks.

Qaqarot / qaqarot