what is the point of this? you can just import inside function definitions: def antislash(A, b): from numpy.linalg import solve return solv

what is the point of this? you can just import inside function definitions: def antislash(A, b): from numpy.linalg import solve return solve(A, b) thus numpy.linalg is only imported the first time you call the antislash function. Much cleaner than a global import. Ignore wrong traditions. Put all imports in the innermost scopes of your code!