Am 08.08.19 um 01:18 schrieb MRAB:
On 2019-08-07 21:36, Kuyateh Yankz wrote:
#trying to write a function that takes a list value as an argument and
returns a string with all the items separated by a comma and a space,
with and inserted before the last item. For example, passing the
previous spam list to the function would return 'apples, bananas,
tofu, and cats'. But your function should be able to work with any
list value passed to it.
def myList(aParameter): #defined
finalList = []
for i in range(len(aParameter)-1): #targeting the last item in
the list
finalList.append('and '+ aParameter[-1]) #Removes the last item
in the list, append the last item with THE and put it back, then put
it into the FINAL LIST FUNCTION.
return finalList
spam = ['apples', 'bananas', 'tofu', 'cats']
print(myList(spam))
#Got up to this point, still couldn't get rid of the '' around the
items and the []. I tried (','.join()) but could not get there.
#Am I on the wrong path or there's a quick fix here?
https://pastebin.com/JCXisAuz
There's a nice way of doing it using str.join. However, you do need to
special-case when there's only 1 item.
Start with a list:
>>> spam = ['apples', 'bananas', 'tofu', 'cats']
The last item will be have an 'and', so let's remove that for the moment:
>>> spam[ : -1]
['apples', 'bananas', 'tofu']
Join these items together with ', ':
>>> ', '.join(spam[ : -1])
'apples, bananas, tofu'
Now for the last item:
>>> ', '.join(spam[ : -1]) + ' and ' + spam[-1]
'apples, bananas, tofu and cats'
For the special case, when len(spam) == 1, just return spam[0].
I think the special case treatment could be avoided.
First: Join all items with ' and '
Second: Replace all ' and ' with ', ' except the last
>>> spam = ['apples', 'bananas', 'tofu', 'cats']
>>> s = " and ".join(spam)
>>> s.replace(" and ", ", ", len(spam) - 2) # except the last
'apples, bananas, tofu and cats'
Or as a one liner:
" and ".join(spam).replace(" and ", ", ", len(spam) - 2)
It works also for a single item list:
>>> spam = ['apples']
'apples'
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