All numpy methods put in local namespace of Macro
In the following code, pvs.Show() leads to the equivalent of from numpy import * being executed on the same line.
As a result, my variable source is redefined to be the function numpy.source.
import paraview.simple as pvs
source = pvs.ProgrammableSource()
source.Script = "import numpy as np"
print(len(locals())) # 9
print(source) # <paraview.servermanager.ProgrammableSource object at 0x128d238b0>
pvs.Show(source)
print(source) # <function source at 0x12848e550>
print(len(locals())) # 638