CODEWITHSUNDEEP
python
Kumar Pushkar
Kumar Pushkar

Reputation: 33

Identifying common element in list in python

I have two lists. I need to compare elements whether any element in the list is matching or not. Input:

a = ['1001,1715']
b = ['1009,1715']

Output : 1715

Please suggest how to do it? I tried doing:

set(''.join(a))

and

set(''.join(b))

but it gave me {'5', '0', '7', ',', '1'}. how can I convert ['1001,1715'] to [1001,1715] ?

Upvotes: 3

Views: 149

Answers (4)

Joe
Joe

Reputation: 12417

A more general solution if you have lists with more elements (e.g a = ['1001,1715','1009,2000'] )

a = [x for xs in a for x in xs.split(',')]
b = [x for xs in b for x in xs.split(',')]
common = set(a).intersection(set(b))

Example:

a = ['1001,1715','1009,2000']
b = ['1009,1715']

Output:

{'1009', '1715'}

Upvotes: 0

Naor Tedgi
Naor Tedgi

Reputation: 5699

a = ['1001,1715']
b = ['1009,1715']

def fun(a):
  return a[0].split(",")

def intersect(a, b):
  return list(set(a) & set(b))

print(intersect(fun(a),fun(b)))

Upvotes: 2

jpp
jpp

Reputation: 164623

There are 2 parts to your problem.

Convert strings to sets of integers

Since your string is the only element of a list, you can use list indexing and str.split with map:

a_set = set(map(int, a[0].split(',')))
b_set = set(map(int, b[0].split(',')))

Calculate the intersection of 2 sets

res = a_set & b_set
# alternatively, a_set.intersection(b_set)

print(res)

{1715}

Upvotes: 0

ernest_k
ernest_k

Reputation: 45309

You can use set intersection:

set(a[0].split(',')).intersection(set(b[0].split(',')))

Which returns:

{'1715'}

Converting from '1001,1715' to ['1001', '1715'] can simply be done with .split(',')

Upvotes: 0

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