CODEWITHSUNDEEP
pythonlistmerge
user3602179
user3602179

Reputation: 67

Combining two lists

I am trying to merge 2 lists like so

coordinates_X = [1, 17, 9]
coordinates_Y = [3, 5, 24]

outcome = [1, 3, 17, 5, 9, 24]

Upvotes: 0

Views: 1411

Answers (4)

pah
pah

Reputation: 4778

If ordering isn't required, you can do:

coordinates_X + coordinates_Y

Also, you can use list comprehensions to output exactly what you 

[ x for y in map(lambda x, y: [x, y], coordinates_X, coordinates_Y) for x in y ]

Probably not the best way to do it, but it was what occurred to me :).

Upvotes: 1

kmacinnis
kmacinnis

Reputation: 638

An alternate without itertools:

result = []
for i in zip(coordinates_X,coordinates_Y):
    result.extend(i)

Upvotes: 2

saudi_Dev
saudi_Dev

Reputation: 839

** the Code you can use is: **

  coordinates_X = [1, 17, 9]
    coordinates_Y = [3, 5, 24]

    outcome =coordinates_X+coordinates_Y

Upvotes: 1

Peter DeGlopper
Peter DeGlopper

Reputation: 37319

Are the lists always the same length? If so, this will give you a list of tuples:

outcome = zip(coordinates_X, coordinates_Y)

You can then flatten that:

import itertools
outcome = list(itertools.chain.from_iterable(zip(coordinates_X, coordinates_Y)))

For 2.x, itertools also has izip available, which builds an iterable yielding tuples. But that's unnecessary for lists this small. On 3.x, zip always returns an iterable.

If they're not the same length, zip or itertools.izip will truncate the outcome to match the shorter list. itertools.izip_longest can extend a shorter list with a fill value specified in the call, if you need that.

Upvotes: 3

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