Remove empty keys in a python list

[BashBedlam]

I couldn't figure out how to do it with list comprehension but here's something that at least does the job.

a = [
    {
        "type": "some.type2",
        "payload": {
            "column1": "12345",
            "column2": "description",
            "column3": 98
        }
    },
    {
        "type": "some.type2",
        "payload": {
            "column1": "12345",
            "column2": "description",
            "column3": 180
        }
    },
    {
        "type": "some.type2",
        "payload": {
            "column1": "12345",
            "column2": "description",
            "column3": ""
        }
    }    
]
z = [] 

for dictionary in a :
	for value in dictionary ['payload'].values () :
		if value == '' :
			break
	else :
		z.append (dictionary)

for dictionary in z :
	print (dictionary)