在python中,为什么我不能在print函数中使用extend函数?
如果我这样写代码在python中,为什么我不能在print函数中使用extend函数?,python,list,printing,extend,Python,List,Printing,Extend,如果我这样写代码 friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "Azmain"] lucky_numbers = [114, 151, 172, 7, 1, 63, 14, 543] friends.extend(lucky_numbers) print(friends) friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "
friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "Azmain"]
lucky_numbers = [114, 151, 172, 7, 1, 63, 14, 543]
friends.extend(lucky_numbers)
print(friends)
friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "Azmain"]
lucky_numbers = [114, 151, 172, 7, 1, 63, 14, 543]
print(friends.extend(lucky_numbers))
然后我的代码运行得很好。但是如果我像这样在打印函数中使用扩展函数
friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "Azmain"]
lucky_numbers = [114, 151, 172, 7, 1, 63, 14, 543]
friends.extend(lucky_numbers)
print(friends)
friends = ["Kafi", "Saif", "Shaheer", "Azmain", "Labid", "Faiz", "Azmain"]
lucky_numbers = [114, 151, 172, 7, 1, 63, 14, 543]
print(friends.extend(lucky_numbers))
然后我得到“无”作为输出。为什么我不能在打印函数中使用extend函数?extend是一个不返回任何内容的就地函数。 打印未返回任何内容的函数的输出将为您提供
None
如果您不想更改朋友
,请复制一份
newfriends = friends.copy()
newfriends.extend(lucky_numbers)
print(newfriends)
您的打印语句打印朋友的返回信息。扩展(幸运数字),它是无的。 从文档中: array.extend(iterable)- 将iterable中的项追加到数组的末尾 因此
extend()