WxPython on Python3

python37Packages.wxPython is missing only python27Packages.wxPython exists.
how can I download wxpython for python3 ?

that requires wxPython 4.0, see

It took the whole day (because I’m new to nixos world) but finally I got it works.
This is the .nix file I used for that with help from the link you gave me:

{ pkgs ? import <nixpkgs> {} }:
(pkgs.buildFHSUserEnv {
  name = "wx-env";
  multiPkgs = pkgs: (with pkgs;
  [ gcc
    pango
    cairo
    gdk_pixbuf
    glib
    xorg.libX11
    xorg.libXxf86vm
    xorg.libSM
    python3
    wxGTK
    gtk3
    zlib
    libpng12
    fribidi
    atk
    cairo
    pango
    which
    doxygen
    libjpeg
    libtiff
    SDL
    gst-plugins-base
    libnotify
    freeglut
    ncurses
    libpng
    gstreamer
    python37Packages.pathlib2
    python37Packages.requests
    python37Packages.pyopengl
    python37Packages.pip
    python37Packages.numpy
    python37Packages.pillow
    python37Packages.six
  ]);
  runScript = "bash";
}).env

in the env itself I used pip to get wxpython:

pip3 install --user -f https://extras.wxpython.org/wxPython4/extras/linux/gtk3/fedora-28 wxPython

I tried ubuntu version but it failed due to missing libjpeg8 … anyway fedora version works.

Simple note for new users like me:

If it says no enough space left, just change TMPDIR environment variable to anywhere else.