I have two lists:
x = [['a', 1], ['b', 2], ['c', 3]]
y = [['a', 4], ['c', 6]]
I would like to keep only the common elements of the letters and combine the 2 lists into:
[['a', 1, 4], ['c', 3, 6]]
How can I do that?
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9you can do anything. What have you tried ?Nagri– Nagri2012-09-06 11:56:10 +00:00Commented Sep 6, 2012 at 11:56
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3 Answers
>>> x = [['a', 1], ['b', 2], ['c', 3]]
>>> y = [['a', 4], ['c', 6]]
>>> lazy = dict
>>> lazyx = lazy(x)
>>> lazyy = lazy(y)
>>> [[lazy, lazyx[lazy], lazyy[lazy]] for lazy in lazyx if lazy in lazyy]
[['a', 1, 4], ['c', 3, 6]]
Comments
Something like this (untested):
Z=[]
for x1, x2 in x:
for y1, y2 in y:
if x1 == y1:
z.append([x1, x2, y2])
Comments
A dictionary is generally a lot better for these kinds of things.
z = {}
for key, val in x + y:
z[key] = z.get(key, []) + [val]
print z #{'a': [1, 4], 'c': [3, 6], 'b': [2]}
print a["b"] #[2]
print a["c"] #[3, 6]
