when splitted in "-", the version is [1:-3] part

PyQt5-5.7.1-5.7.1-cp34.cp35.cp36-none-win_amd64.whl ==> version "5.7.7-5.7.1"
matplotlib-2.0.0-1-cp27-cp27m-manylinux1_x86_64.whl ==> version "2.0.0-1"
numpy-1.11.3+mkl-cp34-cp34m-win32.whl ==> version "1.11.3+mkl"