“只能加入一个可迭代的”python 错误
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"Can only join an iterable" python error
提问by Derek
I've already looked at this post about iterable python errors:
我已经看过这篇关于可迭代 python 错误的文章：
"Can only iterable" Python error
But that was about the error "cannot assign an iterable". My question is why is python telling me:
但那是关于错误“无法分配可迭代的”。我的问题是为什么 python 告诉我：
"list.py", line 6, in <module>
reversedlist = ' '.join(toberlist1)
TypeError: can only join an iterable
I don't know what I am doing wrong! I was following this thread:
我不知道我做错了什么！我正在关注这个线程：
Reverse word order of a string with no str.split() allowed
and specifically this answer:
特别是这个答案：
>>> s = 'This is a string to try'
>>> r = s.split(' ')
['This', 'is', 'a', 'string', 'to', 'try']
>>> r.reverse()
>>> r
['try', 'to', 'string', 'a', 'is', 'This']
>>> result = ' '.join(r)
>>> result
'try to string a is This'
and adapter the code to make it have an input. But when I ran it, it said the error above. I am a complete novice so could you please tell me what the error message means and how to fix it.
并调整代码以使其具有输入。但是当我运行它时，它说上面的错误。我是一个完整的新手，所以请您告诉我错误消息的含义以及如何修复它。
Code Below:
代码如下：
import re
list1 = input ("please enter the list you want to print")
print ("Your List: ", list1)
splitlist1 = list1.split(' ')
tobereversedlist1 = splitlist1.reverse()
reversedlist = ' '.join(tobereversedlist1)
yesno = input ("Press 1 for original list or 2 for reversed list")
yesnoraw = int(yesno)
if yesnoraw == 1:
print (list1)
else:
print (reversedlist)
The program should take an input like apples and pears and then produce an output pears and apples.
该程序应该接受像 apples 和 pears 这样的输入，然后产生一个输出 pears and apples。
Help would be appreciated!
帮助将不胜感激！
采纳答案by Daniel Roseman
splitlist1.reverse(), like many list methods, acts in-place, and therefore returns None. So tobereversedlist1is therefore None, hence the error.
splitlist1.reverse()，像许多列表方法一样，就地执行，因此返回None。因此，tobereversedlist1因此没有，因此错误。
You should pass splitlist1directly:
你应该splitlist1直接通过：
splitlist1.reverse()
reversedlist = ' '.join(splitlist1)
回答by Eds_k
string join must satisfy the connection object to be iterated(list, tuple)
string join 必须满足要迭代的连接对象(list, tuple)
splitlist1.reverse() returns None, None object not support iteration.
splitlist1.reverse() 返回 None，None 对象不支持迭代。
