Robert Berman wrote:
Hi,
Assuming a list similar to this: l1=[['a',1],['b',2],['c',3]] and I want
to get the index of 'c'.
You will need to explain what you mean by "the index of 'c'".
Do you mean 0, because 'c' is in position 0 of the sub-list ['c', 3]?
Or do you mean 2, because 'c' is in the sub-list at position 2?
What happens if there is a sub-list ['d', 'c']? Should that also count? What
about sub-sub-lists, should they be checked too?
Here is a version which checks each sub-list in turn, and returns the index of
any 'c' it finds of the first such sub-list.
def inner_find(list_of_lists):
for sublist in list_of_lists:
try:
return sublist.index('c')
except ValueError:
pass # go to the next one
# If not found at all:
raise ValueError('not found')
Here's a version which finds the index of the first sub-list that begins with
'c' as the zeroth element:
def match_sublist(list_of_lists):
for i, sublist in enumerate(list_of_lists):
if sublist and sublist[0] == 'c':
return i
raise ValueError('not found')
Other variations on these two techniques are left for you to experiment with.
--
Steven
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