With python3-PyYAML 5.1.2 installed, I get:

# docker-compose -h
Traceback (most recent call last):
  File "/usr/bin/docker-compose", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3123,
in <module>
    @_call_aside
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3107,
in _call_aside
    f(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 3136,
in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 580,
in _build_master
    return cls._build_from_requirements(__requires__)
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 593,
in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/usr/lib/python2.7/site-packages/pkg_resources/__init__.py", line 781,
in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'PyYAML<4,>=3.10' distribution was not
found and is required by docker-compose



Here are the available python3-PyYAML versions:

# zypper se -s python3-PyYAML
Loading repository data...
Reading installed packages...

S  | Name           | Type    | Version           | Arch   | Repository         
---+----------------+---------+-------------------+--------+--------------------------
i+ | python3-PyYAML | package | 5.1.2-lp151.2.3.1 | x86_64 |
openSUSE-Leap-15.1-Update
v  | python3-PyYAML | package | 3.13-lp151.1.1    | x86_64 |
openSUSE-Leap-15.1-Oss   
v  | python3-PyYAML | package | 5.1.2-lp151.2.3.1 | i586   |
openSUSE-Leap-15.1-Update