I entered this code in terminal but nothing happened.

sudo ln -s /usr/include/locale.h /usr/include/xlocale.

After then, I entered below code and got an error.

pip3 install h5py==3.1.0

Error is below.

Error said cannot find a version of 3.1.0 but it showed 3.1.0 in example. I can’t understand what is problem.

Defaulting to user installation because normal site-packages is not writeable
Collecting h5py==3.1.0
  Using cached h5py-3.1.0.tar.gz (371 kB)
  Installing build dependencies ... error
  ERROR: Command errored out with exit status 1:
   command: /usr/bin/python3 /usr/local/lib/python3.6/dist-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-92wl28ep/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel
       cwd: None
  Complete output (35 lines):
  Traceback (most recent call last):
    File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
      "__main__", mod_spec)
    File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
      exec(code, run_globals)
    File "/usr/local/lib/python3.6/dist-packages/pip/__main__.py", line 27, in <module>
      "ignore", category=DeprecationWarning, module=".*packaging\.version"
    File "/usr/lib/python3.6/warnings.py", line 131, in filterwarnings
      import re
    File "/usr/lib/python3.6/re.py", line 142, in <module>
      class RegexFlag(enum.IntFlag):
  AttributeError: module 'enum' has no attribute 'IntFlag'
  Error in sys.excepthook:
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 62, in apport_excepthook
      if not enabled():
    File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 24, in enabled
      import re
    File "/usr/lib/python3.6/re.py", line 142, in <module>
      class RegexFlag(enum.IntFlag):
  AttributeError: module 'enum' has no attribute 'IntFlag'
  
  Original exception was:
  Traceback (most recent call last):
    File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
      "__main__", mod_spec)
    File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
      exec(code, run_globals)
    File "/usr/local/lib/python3.6/dist-packages/pip/__main__.py", line 27, in <module>
      "ignore", category=DeprecationWarning, module=".*packaging\.version"
    File "/usr/lib/python3.6/warnings.py", line 131, in filterwarnings
      import re
    File "/usr/lib/python3.6/re.py", line 142, in <module>
      class RegexFlag(enum.IntFlag):
  AttributeError: module 'enum' has no attribute 'IntFlag'
  ----------------------------------------
WARNING: Discarding https://files.pythonhosted.org/packages/a7/81/20d5d994c91ed8347efda90d32c396ea28254fd8eb9e071e28ee5700ffd5/h5py-3.1.0.tar.gz#sha256=1e2516f190652beedcb8c7acfa1c6fa92d99b42331cbef5e5c7ec2d65b0fc3c2 (from https://pypi.org/simple/h5py/) (requires-python:>=3.6). Command errored out with exit status 1: /usr/bin/python3 /usr/local/lib/python3.6/dist-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-92wl28ep/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel Check the logs for full command output.
ERROR: Could not find a version that satisfies the requirement h5py==3.1.0 (from versions: 2.2.1, 2.3.0b1, 2.3.0, 2.3.1, 2.4.0b1, 2.4.0, 2.5.0, 2.6.0, 2.7.0rc2, 2.7.0, 2.7.1, 2.8.0rc1, 2.8.0, 2.9.0rc1, 2.9.0, 2.10.0, 3.0.0rc1, 3.0.0, 3.1.0)
ERROR: No matching distribution found for h5py==3.1.0

What is problem of this code and how can I solve it?