Combining two string lists

Question

Looking to combine two list variables containing string elements. For example, if I have the below :

mystring1 = ['Luke', 'Han']
mystring2 = ['Skywalker', 'Solo']

I am looking to combine them to be :

mystring3 = ['LukeSkywalker', 'HanSolo']

I am sure I am missing something simple. Any guidance would be great!

consider accepting an answer. Doesn't necessarily have to be my answer, but the one you found most useful. — Paul Rooney, Jul 28 '18 at 08:00

blhsing · Answer 1 · 2018-07-18T03:53:21.810

9

Simply map the two lists to str.__add__:

list(map(str.__add__, mystring1, mystring2))

This outputs:

['LukeSkywalker', 'HanSolo']

As a side note, if you want to combine more than two lists of strings at a time, you can do:

mystring1 = ['Luke', 'Han']
mystring2 = ['Skywalker', 'Solo']
mystring3 = ['Hero', 'Sidekick']
from functools import partial, reduce
print(list(reduce(partial(map, str.__add__), (mystring1, mystring2, mystring3))))

This outputs:

['LukeSkywalkerHero', 'HanSoloSidekick']

edited Jul 18 '18 at 03:53

answered Jul 18 '18 at 03:31

blhsing

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Great I never knew `map` took multiple iterables. You could remove the need for using the dunder method if you used [`operator.add`](https://docs.python.org/3.7/library/operator.html#operator.add) – Paul Rooney Jul 18 '18 at 03:36
thank you!!! this is great. – JDV_ny Jul 18 '18 at 10:16
@JDV_ny Glad to be of help. Can you mark this answer as accepted if you think it is correct? – blhsing Jul 18 '18 at 10:58

Pankaj Singhal · Answer 2 · 2018-07-18T13:44:18.773

5

The following should work:

>>> mystring1 = ['Luke', 'Han']
>>> mystring2 = ['Skywalker', 'Solo']
>>> list(map(''.join, zip(mystring1, mystring2)))
['LukeSkywalker', 'HanSolo']
>>>

edited Jul 18 '18 at 13:44

answered Jul 18 '18 at 03:24

Pankaj Singhal

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`list(map(''.join, zip(mystring1, mystring2)))`. No need to map `str` over anything. – Brad Solomon Jul 18 '18 at 03:33
@BradSolomon removed the outer `list()` also coz `zip()` returns list itself – Pankaj Singhal Jul 18 '18 at 06:06
In Python 2, yes. In Python 3, you need `list()`. – Brad Solomon Jul 18 '18 at 12:37
ok. Added then. – Pankaj Singhal Jul 18 '18 at 13:44

Paul Rooney · Answer 3 · 2018-07-28T08:48:50.870

Just use zip and then concatenate the strings.

This obviously only works if there are exactly two strings you wish to join. If there were more, then use str.join like some of the other answers suggest. With 2 strings however the concat method is more readable.

>>> mystring1 = ['Luke', 'Han']
>>> mystring2 = ['Skywalker', 'Solo']
>>> 
>>> [s1 + s2 for s1, s2 in zip(mystring1, mystring2)]
['LukeSkywalker', 'HanSolo']

zip simply takes one element from each of the iterables passed to it, on each iteration and returns a tuple of those elements. The intermediate result of the zip operation looks like

[('Luke', 'Skywalker'), ('Han', 'Solo')]

score 1 · Answer 4 · answered Jul 18 '18 at 03:22

1

map(lambda x: x[0] + x[1], zip(mystring1, mystring2))

Zipping the two produces an iterable (or list, if you're in Python 2) of 2-tuples. Then map over the iterable (resp. list) to convert to the result you want.

answered Jul 18 '18 at 03:22

Silvio Mayolo

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You can also do `map(lambda x, y: x + y, mystring1, mystring2)`. – RoadRunner Jul 18 '18 at 04:44

score 1 · Answer 5 · answered Jul 18 '18 at 03:37

1

import pandas as pd
mystring1 = ['Luke', 'Han']
mystring2 = ['Skywalker', 'Solo']
df=pd.DataFrame([mystring1,mystring2]).T
df.columns=list('01')
print((df['0']+df['1']).tolist())

Output:

['LukeSkywalker', 'HanSolo']

answered Jul 18 '18 at 03:37

U13-Forward

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Combining two string lists

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