Python-リストから重複を削除する方法

リストは重要なコンテナであり、Web開発だけでなく、日常のプログラミングのほとんどすべてのコードで使用されます。リストを使用すればするほど、リストを習得するための要件が​​増えるため、リストの操作に関する知識が必要になります。リストから重複を削除する操作には多数のアプリケーションがあるため、その知識があると便利です。

例

# using naive methods
# initializing list
test_list = [1, 3, 5, 6, 3, 5, 6, 1]
print ("The original list is : " +  str(test_list))
# using naive method to remove duplicated from list
res = []
for i in test_list:
   if i not in res:
      res.append(i)
# printing list after removal
print ("The list after removing duplicates : " + str(res))
# using list comprehension
# initializing list
test_list = [1, 3, 5, 6, 3, 5, 6, 1]
print ("The original list is : " +  str(test_list))
# using list comprehension to remove duplicated from list
res = []
[res.append(x) for x in test_list if x not in res]
# printing list after removal
print ("The list after removing duplicates : " + str(res))
# using set()
# initializing list
test_list = [1, 5, 3, 6, 3, 5, 6, 1]
print ("The original list is : " +  str(test_list))
# using set() to remove duplicated from list
test_list = list(set(test_list))  
# printing list after removal
print ("The list after removing duplicates : " + str(test_list))
# using list comprehension + enumerate()
# initializing list
test_list = [1, 5, 3, 6, 3, 5, 6, 1]
print ("The original list is : " +  str(test_list))
# using list comprehension + enumerate() to remove duplicated from list
res = [i for n, i in enumerate(test_list) if i not in test_list[:n]]  
# printing list after removal
print ("The list after removing duplicates : " + str(res))
# using collections.OrderedDict.fromkeys()
from collections import OrderedDict
# initializing list
test_list = [1, 5, 3, 6, 3, 5, 6, 1]
print ("The original list is : " +  str(test_list))  
# using collections.OrderedDict.fromkeys() to remove duplicated from list
res = list(OrderedDict.fromkeys(test_list))  
# printing list after removal
print ("The list after removing duplicates : " + str(res))

出力

The original list is : [1, 3, 5, 6, 3, 5, 6, 1]
The list after removing duplicates : [1, 3, 5, 6]
The original list is : [1, 3, 5, 6, 3, 5, 6, 1]
The list after removing duplicates : [1, 3, 5, 6]
The original list is : [1, 5, 3, 6, 3, 5, 6, 1]
The list after removing duplicates : [1, 3, 5, 6]
The original list is : [1, 5, 3, 6, 3, 5, 6, 1]
The list after removing duplicates : [1, 5, 3, 6]
The original list is : [1, 5, 3, 6, 3, 5, 6, 1]
The list after removing duplicates : [1, 5, 3, 6]