Comparing two separate string inputs and finding what they have in common

Question

I am sure there is a better way to describe my problem (hence why I haven't found much on google), but I want to compare two separate strings and pull the substrings they have in common.

Say I have a function that takes two arguments, "hello,world,pie" and "hello,earth,pie"

I want to return "hello,pie"

How could I do this? Here is what I have so far

def compare(first, second):
    save = []
    for b, c in set(first.split(',')), set(second.split(',')):
        if b == c:
             save.append(b)




compare("hello,world,pie", "hello,earth,pie")

Use the [intersection](https://docs.python.org/2/library/stdtypes.html#frozenset) of those two sets. — VHarisop, Jan 12 '15 at 01:19

score 0 · Accepted Answer · answered Jan 12 '15 at 01:17

0

try like this:

>>> def common(first, second):
...     return list(set(first.split(',')) & set(second.split(',')))
... 
>>> common("hello,world,pie", "hello,earth,pie")
['hello', 'pie']

answered Jan 12 '15 at 01:17

Hackaholic

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score 0 · Answer 2 · answered Jan 12 '15 at 01:20

0

>>> a = "hello,world,pie"
>>> b = "hello,earth,pie"
>>> ','.join(set(a.split(',')).intersection(b.split(',')))
'hello,pie'

answered Jan 12 '15 at 01:20

jamylak

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downvoter please explain what is wrong. I returned the output string given in the question – jamylak Jan 12 '15 at 01:29

score 0 · Answer 3 · answered Jan 12 '15 at 01:23

0

try this

a="hello,world,pie".split(',')
b="hello,earth,pie".split(',')

print  [i for i in a if i in b]

answered Jan 12 '15 at 01:23

Ash

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score 0 · Answer 4 · answered Jan 12 '15 at 01:26

0

use set() & set():

def compare(first, second):
    return ','.join(set(first.split(',')) & set(second.split(','))) 

compare("hello,world,pie", "hello,earth,pie")
'hello,pie'

answered Jan 12 '15 at 01:26

Anzel

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Comparing two separate string inputs and finding what they have in common

4 Answers4