tasks_of_project.py

from collections import OrderedDict
members = [
  #{'name': 'member', 'skills': set('skill1', 'skill2', ...)}
  {'name': 'Jan', 'skills': set(('PHP', 'HTML'))},
  {'name': 'Bep', 'skills': set(('HTML', 'CSS'))},
  {'name': 'Leo', 'skills': set(('CSS', 'PHP'))}
]
project = OrderedDict([
  #'task': ['skill', nrhourswork]
  ('A', ['PHP', 2]),
  ('B', ['HTML',3]),
  ('C', ['CSS', 4]),
  ('D', ['PHP', 3]),
  ('E', ['HTML',2]),
  ('F', ['CSS', 4]),
])

hours_by_member = {}
for member_data in members:
  member_name = member_data['name']
  member_skills = member_data['skills']
  for task, skill_and_hours in project.items():
    skill = skill_and_hours[0]
    hours = skill_and_hours[1]
    if skill in member_skills:
      if member_name not in hours_by_member:
        hours_by_member[member_name] = []
      hours_by_member[member_name].append(hours)

for member_name, hours_list in hours_by_member.items():
  hours_list.sort(reverse=True)

hours_by_member = OrderedDict(hours_by_member)

summary = 0
while len(hours_by_member):
  parallel_hours = [hours_list[0] for mname, hours_list in hours_by_member.items() if len(hours_list) > 0]
  min_hours = min(parallel_hours)
  for mname, hours_list in hours_by_member.items():
      if hours_list[0] > min_hours:
        hours_list[0] -= min_hours
      else:
        del hours_list[0]
        if len(hours_list) == 0:
          del hours_by_member[mname]
  summary += min_hours

print('Summary time: %d hours' % summary)