def popen3(cmd, bufsize=-1, mode='t'):
        inst = Popen3(cmd, True, bufsize)
        return inst.fromchild, inst.tochild, inst.childerr
The Cartan matrix for F_4
dataset/ETHPy150Open azoft-dev-team/imagrium/env/Lib/popen2.py/popen3--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/liealgebras/type_f.py/TypeF.cartan_matrix