I have a list of lists in my Python 3:
mylist = [[a,x,x][b,x,x][c,x,x]]
(x is just some data)
I have my code which does that:
for sublist in mylist:
if sublist[0] == a:
sublist[1] = sublist[1]+1
break
now I want to add an entry, if there is any sublistentry ==a
How can I do that?
Use any()
to test the sublists:
if any(a in subl for subl in mylist):
This tests each subl
but exits the generator expression loop early if a match is found.
This does not , however, return the specific sublist that matched. You could use next()
with a generator expression to find the first match:
matched = next((subl for subl in mylist if a in subl), None)
if matched is not None:
matched[1] += 1
where None
is a default returned if the generator expression raises a StopIteration
exception, or you can omit the default and use exception handling instead:
try:
matched = next(subl for subl in mylist if a in subl)
matched[1] += 1
except StopIteration:
pass # no match found
您可以将any()
与列表推导一起使用(好吧,这里是生成器推导):
inList = any(a in sublist for sublist in mylist)
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