Python列表输入2个相同的单词，如何只打印一次

Question

Hi first time posting here, I am trying to make a list that only prints an input once. For example if the user enters: car dog dog house car then your program should display: car dog house

wordlist = []
while True:
  word  = (input("Enter a word (blank to quit): "))
  wordlist.append(word)
  if word == wordlist:
   wordlist.remove(word)
  if word == "":
     break

for word in wordlist:
    print(word)

I also tried

if word == wordlist:
    wordlist[-1]

Any help would be great.

Answer 1

If order of words does not matter use set

wordlist = set()
while True:
    word  = (input("Enter a word (blank to quit): "))
    if word == "":
        break
    wordlist.add(word)

for word in wordlist:
    print(word)

If order of insertion of word matters append the list with condition

wordlist = []
while True:
    word  = (input("Enter a word (blank to quit): "))
    if word == "":
        break
    if word not in wordlist:
        wordlist.append(word)

for word in wordlist:
    print(word)

If you want to keep the duplicates but just want to remove while printing

for word in set(wordlist):
    print(word)

If orders need to be maintained while printing

visited=set()
for word in wordlist:
    if word not in visited:
        print(word)
        visited.add(word)

Answer 2

In [49]: words = 'car dog dog house car'.split()                                           

In [50]: from collections import OrderedDict                                               

In [51]: word_dict = OrderedDict()                                                         

In [52]: for word in words: 
    ...:     word_dict[word] = None 
    ...:                                                                                   

In [53]: for word in word_dict: 
    ...:     print(word) 
    ...:                                                                                   
car
dog
house

Answer 3

You can try following:

wordlist = []
while True:
  word  = (input("Enter a word (blank to quit): "))
  if not word:
    break
  elif word not in wordlist:
    wordlist.append(word)

for word in wordlist:
    print(word)