Difference between .items() and .keys()
python
Solution
The first method is arguably clearer and easier to read, so I would always recommend it over the latter.
That said, in a simple case like this, the better option would be a dictionary comprehension:
{k: v if v is not None else "" for k, v in mydict.items()}
It's worth a note that the second example can be simplified, as iterating directly over `mydict` will provide the keys, so no need for `mydict.keys()` (which is mainly useful for when you want the set of keys for another purpose, not iteration).
(As jathanism notes in the comments, in older versions of Python (2.x), using `iteritems()` is a better option than `items()` as it does not produce a list - 3.x users like myself don't need to worry as `items()` produces a dictionary view, which is lazy.)
Problem
Is there any advantage to using the first block of code over the second one when iterating over a dictionary? ``` for k, v in mydict.items(): if v == None: mydict[k] = '' ``` and ``` for k in mydict.keys(): if mydict[k] == None: mydict[k] = '' ```