在添加时，python Append值被多次添加到列表中

Question

from itertools import permutations, product


def sensitivity_analysis(a,b):
    length_a=len(a.keys())
    length_b=len(b.keys())
    items_a=list(a.keys())
    items_b=list(b.keys())
    a_variants = [dict(zip(items_a, values)) 
                 for values in product((list(p) for p in permutations(items_b)), repeat=length_a)]
    b_variants = [dict(zip(items_b, values)) 
                 for values in product((list(v) for v in permutations(items_a)), repeat=length_b)]

    all_variants = product(a_variants, b_variants)
    contains_a=[]
    contains_b=[]
    for i,j in all_variants:
        contains_a.append(i)
        contains_b.append(j)
    return contains_a,contains_b

def insert_dummies(a,b):
  length_a=len(a.keys())
  length_b=len(b.keys())
  items_a=list(a.keys())
  items_b=list(b.keys())
  dummy_list=[]
  if length_a>length_b:
    dummy_number=length_a-length_b
    nummer=1
    while nummer<dummy_number+1:
        dummy_list.append("Dummy%d" %nummer)
        nummer=nummer+1
    for i in items_a:
      f=0
      while dummy_number>f:
        a.setdefault(i,[]).append(dummy_list[f])
        f=f+1
    n=0    
    while n<(dummy_number):
      for z in dummy_list:
        b[z]=items_a
        n=n+1
  if length_a<length_b:
    dummy_number=length_b-length_a
    nummer=1
    while nummer<dummy_number+1:
        dummy_list.append("Dummy%d" %nummer)
        nummer=nummer+1
    for i in items_b:
      f=0
      while dummy_number>f:
        b.setdefault(i,[]).append(dummy_list[f])
        f=f+1
    n=0    
    while n<(dummy_number):
      for z in dummy_list:
        a[z]=items_b
        n=n+1
    else:
        return

  return a,b

ab={"kart":["marie","alice"],
"vinod":["alice","marie"],
"jordan":["marie","alice"],
"joe":["marie","alice"]}
ba={"alice":["kart","vinod","joe","jordan"],
"marie":["kart","vinod","jordan","joe"]}

thelist1=sensitivity_analysis(ab,ba)[0]
thelist2=sensitivity_analysis(ab,ba)[1]
insert_dummies(thelist1[0],thelist2[0])

我这里有两个功能。一种是灵敏度分析，它返回两个字典ab和ba的所有可能组合。insert\u dummies函数打算通过添加dummies来整理这两个字典。例如，上面的字典在添加了假人之后应该是这样的。你知道吗

{'kart': ['marie', 'alice', 'Dummy1', 'Dummy2'],
  'vinod': ['alice', 'marie', 'Dummy1', 'Dummy2'],
  'jordan': ['marie', 'alice', 'Dummy1', 'Dummy2'],
  'joe': ['marie', 'alice', 'Dummy1', 'Dummy2']},
 {'alice': ['kart', 'vinod', 'joe', 'jordan'],
  'marie': ['kart', 'vinod', 'jordan', 'joe'],
  'Dummy1': ['kart', 'vinod', 'jordan', 'joe'],
  'Dummy2': ['kart', 'vinod', 'jordan', 'joe']}

但是在这个例子中，dummy 1和dummy 2为dictionary ab中的每个键添加了4次。同样，list1和list2也添加了dummie。我做错什么了？感谢您的帮助！你知道吗

Answer 1

问题是，不知何故，我创建字典的键指向同一个列表，而不是四个相等的列表。这意味着我改变了一个值，所有其他的值似乎也改变了（实际上，它只是一个对象）。你知道吗

我修改了字典结构，使值具有不同的标识，从而解决了这个问题。你知道吗

newdic1 = {k:v[:] for k, v in list1[i].items()}