Python3 Removing dictionary key if value contained in list is blank

Question

So I have a dictionary filled with lots of useful stuff. I would like to remove a key (build a new dict without the key) if any value within a list is empty.

The dictionary:

>>>print(vaar123)
{'moo': 'cora', 'ham': ['', 'test'], 'bye': 2, 'pigeon': '', 'heloo': 1}

I can remove the 'pigeon' key with its empty value with something along the lines of.

>>>dict((k, v) for k, v in vaar123.items() if v)
{'moo': 'cora', 'ham': ['', 'test'], 'heloo': 1, 'bye': 2}

But try as I might, I cannot seem to come up with a method to remove 'ham' as it has an empty value in its list.

Thanks in advance for any suggestions, Frank

Info: The dictionary is built with a value on creation (set by admin) the additional value is added to the list by user input. The value pair is used as output. Having a single value in the list produces undesirable output.

Answer 1

This function recursively checks Sized Iterables to see if they are empty and returns False if it finds one that is

from collections.abc import Sized, Iterable #If you're on Python >= 3.6,
                                            #you can use collections.abc.Collection

def all_nonempty(v):
    if isinstance(v, (Sized, Iterable)):
        return v and (all(map(all_nonempty, v)) if not isinstance(v, str) else True)
        #We do the check against str because 'a' is a sized iterable that
        #contains 'a'.  I don't think there's an abstract class for
        #containers like that
    return True

Then we can use this to winnow the dict

print({k: v for k, v in d.items() if all_nonempty(v)})

outputs:

{'moo': 'cora', 'bye': 2, 'heloo': 1}

Answer 2

Perhaps like this:

>>> d = {'moo': 'cora', 'ham': ['', 'test'], 'heloo': 1, 'bye': 2}
>>> {k:v for k,v in d.items() if not(isinstance(v,list) and len(v) > 0 and v[0] == '')}
{'heloo': 1, 'moo': 'cora', 'bye': 2}

Or maybe just:

>>> {k:v for k,v in d.items() if not(isinstance(v,list) and '' in v)}
{'heloo': 1, 'moo': 'cora', 'bye': 2}

The first answer will remove items where the values are lists in which the first element is ''. The second will remove any value which is a list in which '' occurs somewhere.

Answer 3

Assuming all values in the lists are strings:

{k: v
 for k, v in vaar123.items()
 if (not hasattr(v, '__iter__')) or
    (hasattr(v, '__iter__') and v and all(elem for elem in v))}

Explanation: Keep non-iterable values because they can't be empty (doesn't make sense). Otherwise, if a value is iterable, discard it if it's empty or if it contains any false values (i.e., empty string per the assumption above).