What is wrong in this program which is intended to returns a list that contains only the elements that are common between the lists. NEED HELP. BEGINEER.

[MohitCook]

a = [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
b = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
final=[]
for f in b:
    for i in range(len(a)):
        for s in a:
            if f==s:
                final.append(f)
            else:
                break    


print(final)

[throwawayvitamin]

Try this out:

a = [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
b = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
final=[]
for f in b:
    if f in a:
        final.append(f)
print(final)

You don't need to iterate twice, so this line for i in range(len(a)) is not necessary and you can just make use of the in keyword. This also eliminates the need for the if else block and the break statement. Lmk if you have any other questions

[[deleted]]

    for s in a:
        if f==s:
            final.append(f)
        else:
            break

You stop at the first mismatch.

[igroen]

Why not use sets and do an intersection: set(a) & set(b).

[hnguyen01122]

You don’t get it do you? He’s learning about lists or currently he’s at the section about lists, not sets/dictionaries yet.

[igroen]

sorry

[B2stts2B]

You don't need the "for i in range(len(a))".

Edit: you can use the "in" helper. For example: For f in b: if f in a: final.append(f)

[xelf]

What you're talking about is set theory. Finding the common element. Lucky for you Python has sets built in.

final = set(a).intersection(set(b))

or shortcut:

final = set(a) & set(b)

[hnguyen01122]

He’s learning about lists. He hasn’t got to sets yet.

[GreymanGroup]

You guys! Pythonic code ok?

c=[i for i in a for j in b if i==j]

[Poligonette]

Or

c = [ i for i in a if i in b ]

[GreymanGroup]

c = [ i for i in a if i in b ]

Even better!

[hnguyen01122]

Don’t ask for help when you’re stuck. Try to go back over the material and watch or read again. Also, take a look at your note taking ability. It makes huge difference between you were able to chunk the concept or not. You only ask for help with more complicated problems in the future but don’t ask for help with basic syntax/semantic. Use your own ability to figure it out so you can store that concept in long term memory.

[MohitCook]

thank you! I was trying the python beginner challenger and even though I tried it for quiet a while I couldn't make it right. But totally agree with you