Question

I’ve been teaching myself python and so far it’s hasn’t been too bad. I reckon the easiest way to learn is to just start coding so I’ve come up with relatively simple tasks to help me. And now I’m stuck and it’s getting frustrating not being able to figure out what I’m doing wrong

{0: [[1, '.', 0, '-', 8]], 
1: [['.', 3, '.', 2, 0, 0, 1, '-']], 
2: [], 
3: [['.', '.']], 
4: [], 
5: [[2, 0, 1, 2, '-', 0, 1, '-', 1, 9]], 
6: [[1, '.', 0, 0, 9, 5]], etc...

So I have a dictionary where each key has a value(which are exchange rates for various currency pairs). I’ve been trying to turn the values into a single string so for instance:

0: [[1, '.', 0, '-', 8]] would become 0: '1.0-8'
6: [[1, '.', 0, 0, 9, 5]] would be 6 : '1.0095'
etc...

After numerous hours of trying various methods and googling, I’ve come to the conclusion that I have no idea whatsoever on how to accomplish this. I’ve tried doing a replace, and various complicated loops that turn the dictionary into a list of lists with the key[value] as a list and then trying to iterate over it using a join function etc…and it all has accomplished absolutely nothing!

It seems like it should be simple to do, but I give up, I have no idea how to do this, so hopefully someone here can give me a hand.

Thanks a lot!

Answer 1

One-liner…

>>> {i:(''.join(str(x) for x in j[0]) if j else '') for i,j in d.items()}
{0: '1.0-8', 1: '.3.2001-', 2: '', 3: '..', 4: '', 5: '2012-01-19', 6: '1.0095'}

“writing it in a noob friendly way”, as asked:

d_new = {}
for i,j in d.items():
    if j:
        d_new[i] = ''.join(str(x) for x in j[0])
    else:
        d_new[i] = ''