Das deutsche Python-Forum

Code: Alles auswählen

In [2]: A
Out[2]: 
{'i1': ['s1', 's2', 's3'],
 'i2': ['s1', 's2', 's3'],
 'i3': ['s3', 's2', 's3'],
 's1': ['i1', 'i2', 'i3'],
 's2': ['i1', 'i3', 'i2'],
 's3': ['i1', 'i2', 'i3']}

In [3]: A['s1'].extend(['i2', 'i3', 'i3'])

In [4]: A
Out[4]: 
{'i1': ['s1', 's2', 's3'],
 'i2': ['s1', 's2', 's3'],
 'i3': ['s3', 's2', 's3'],
 's1': ['i1', 'i2', 'i3', 'i2', 'i3', 'i3'],
 's2': ['i1', 'i3', 'i2'],
 's3': ['i1', 'i2', 'i3']}

Code: Alles auswählen

def GaleShapley(teacher,school,pref):
        rank={} 
        for s in school:
                rank[s]={}
                i=1
                for t in pref[s]:
                        rank[s][t]=i
                        i+=1
        #create a pointer to the next school to propose         
        prefptr={}
        for t in teacher:
                prefptr[t]=0
        freeteacher=list(teacher) #all teachers and schools are free
        numpartners=len(teacher) #length teacher
        D={} #Build dicitionary to assign
        #run the algorithm
        while freeteacher:
                t=freeteacher.pop() #last item of the list will be remove and return
                if prefptr[t]>numpartners: continue
                #ueberspringt den befehl wenn if erfüllt zur while schleife
                #get the highest ranked woman that has no been proposed to
                s=pref[t][prefptr[t]]
                prefptr[t]+=1
                if s not in D: D[s]=t
                else:
                        tprime=D[s]
                        if rank[s][t]<rank[s][tprime]:
                                D[s]= t
                                freeteacher.append(tprime)#Add tprime to the end of the list
                        else:
                                freeteacher.append(t)
        

        return D

#test    

if __name__=="__main__":
        theteacher= ['i1','i2','i3']
        theschool= ['s1','s2','s3']
        thepref= {'i1':['s1','s2','s3'],
                  'i2':['s1','s2','s3'],
                  'i3':['s3','s2','s3'],
                  's1':['i1','i2','i3'],
                  's2':['i1','i3','i2'],
                  's3':['i1','i2','i3']}
        eng=GaleShapley(theteacher, theschool, thepref)
        print eng

Code: Alles auswählen

old_list = [1, 2, 3]
new_list = sum(([e, e] for e in old_list), [])
print(new_list)  # -> [1, 1, 2, 2, 3, 3]

Code: Alles auswählen

old_list = [1, 2, 3]
new_list = []
for e in old_list:
    new_list.extend([e, e])
print(new_list)  # -> [1, 1, 2, 2, 3, 3]

Code: Alles auswählen

from itertools import chain

old_list = [1, 2, 3]
new_list = list(
    chain.from_iterable(
        [e, e] for e in old_list
    )
)
print(new_list)  # -> [1, 1, 2, 2, 3, 3]

Code: Alles auswählen

new_list = list(chain.from_iterable(izip(old_list, old_list)))

Code: Alles auswählen

from functools import reduce
from operator import iadd

old_list = [1, 2, 3]
new_list = reduce(iadd, ([e, e] for e in old_list))
print(new_list)  # -> [1, 1, 2, 2, 3, 3]

Code: Alles auswählen

#!/usr/bin/env python
# coding: utf8
from __future__ import absolute_import, division, print_function


def gale_shapley(teachers, schools, preferences):
    if len(teachers) != len(schools):
        raise ValueError('`teachers` and `schools` have not the same length')
    
    rank = dict()
    for school in schools:
        rank[school] = dict(
            (teacher, i) for i, teacher in enumerate(preferences[school], 1)
        )

    teacher2school_index = dict.fromkeys(teachers, 0)
    unassigned_teachers = list(teachers)
    total_school_count = len(schools)
    school2teacher = dict()
    while unassigned_teachers:
        teacher = unassigned_teachers.pop()
        if teacher2school_index[teacher] <= total_school_count:
            # Get the highest ranked school that has not been assigned to.
            school = preferences[teacher][teacher2school_index[teacher]]
            teacher2school_index[teacher] += 1
            if school not in school2teacher:
                school2teacher[school] = teacher
            else:
                assigned_teacher = school2teacher[school]
                if rank[school][teacher] < rank[school][assigned_teacher]:
                    school2teacher[school] = teacher
                    unassigned_teachers.append(assigned_teacher)
                else:
                    unassigned_teachers.append(teacher)
    return school2teacher


def main():
    teachers = ['i1', 'i2', 'i3']
    schools = ['s1', 's2', 's3']
    preferences = {
        'i1': ['s1', 's2', 's3'],
        'i2': ['s1', 's2', 's3'],
        'i3': ['s3', 's2', 's3'],
        's1': ['i1', 'i2', 'i3'],
        's2': ['i1', 'i3', 'i2'],
        's3': ['i1', 'i2', 'i3'],
    }
    school2teacher = gale_shapley(teachers, schools, preferences)
    print(school2teacher)


if __name__ == '__main__':
    main()

Code: Alles auswählen

#!/usr/bin/env python
# coding: utf8
from __future__ import absolute_import, division, print_function


def gale_shapley(teachers, schools, preferences):
    if len(teachers) != len(schools):
        raise ValueError('`teachers` and `schools` have not the same length')
    
    rank = dict()
    for school in schools:
        rank[school] = dict(
            (teacher, i) for i, teacher in enumerate(preferences[school], 1)
        )

    teacher2school_index = dict.fromkeys(teachers, 0)
    unassigned_teachers = list(teachers)
    total_school_count = len(schools)
    school2teacher = dict()
    while unassigned_teachers:
        teacher = unassigned_teachers.pop()
        if teacher2school_index[teacher] <= total_school_count:
            # Get the highest ranked school that has not been assigned to.
            school = preferences[teacher][teacher2school_index[teacher]]
            teacher2school_index[teacher] += 1
            if school not in school2teacher:
                school2teacher[school] = teacher
            else:
                assigned_teacher = school2teacher[school]
                if rank[school][teacher] < rank[school][assigned_teacher]:
                    school2teacher[school] = teacher
                    unassigned_teachers.append(assigned_teacher)
                else:
                    unassigned_teachers.append(teacher)
    return school2teacher


def main():
    teachers = ['i1', 'i2', 'i3']
    schools = ['s1', 's2', 's3']
    preferences = {
        'i1': ['s1', 's2', 's3'],
        'i2': ['s1', 's2', 's3'],
        'i3': ['s3', 's2', 's1'],
        's1': ['i1', 'i2', 'i3'],
        's2': ['i1', 'i3', 'i2'],
        's3': ['i1', 'i2', 'i3'],
    }
    school2teacher = gale_shapley(teachers, schools, preferences)
    print(school2teacher)


if __name__ == '__main__':
    main()

Code: Alles auswählen

l = [1, 2, 3]
print([elem for pair in zip(l, l) for elem in pair])