Remove empty keys in a python list

[python_student]

I have a list of dictionaries and in case if some dictionary has empty key I want to remove it completely from the list. In my example,
I need to remove all third block because column3 is empty.

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": "" } } ]

This is my code but is not removing and I think it's because of json structure

a = [d for d in payload if "" not in d.values()] print(type(a)) <class 'list'>

Does anyone knows how can I solve it?

[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)

[python_student]

I have tried this solution, but did not work. Here is the code I have tried. I have "if conditional" from type because I have others type. This specially is with problem

print(type(a)) payload = json.loads(json.dumps(a)) if type(payload) == list: payload2 = [] for dictionary in payload: for value in dictionary['payload'].value(): if value =='': break else: payload2.append(dictionary) payload = payload2 else: payload = {k:v for (k,v) in payload.items() if v != ""} message['messages'] = payload print(json.dumps( message ))

Any idea?

[ibreeden]

Please elaborate "but did not work". Did you get an error message? Or an unexpected result? Or what.

[deanhystad]

The tricky part is to "flatten" the dictionary so you look at all the keys.

a = [ { "type": "X", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": 1 } }, { "type": "X", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": 0 } }, { "type": "X", "payload": { "column1": "", "column2": [1, 2, 3], "column3": 1 } }, { "type": "X", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": None } }, { "type": "X", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": {} } } ] def empty_key(dictionary): """Recursively scan dictionary for values that are empty collections or None. Return associated key and value or None if no 'empty' values found.""" for key in dictionary.keys(): value = dictionary[key] if value is None: return key, value elif isinstance(value, (list, tuple, set, str)) and not value: return key, value elif isinstance(value, dict): if value: if (value := empty_key(value)): return value else: return key, value # Empty dictionary return None print([x for x in a if empty_key(x) is None])

This is easily expanded to not only scan dictionary values but list, tuple, and set values as well.

a = [ { "type": "Not empty", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": 1 } }, { "type": "Zero, Not empty", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": 0 } }, { "type": "column1 is empty str", "payload": { "column1": "", "column2": [1, 2, 3], "column3": 1 } }, { "type": "column3 is None", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": None } }, { "type": "column3 is empty dictionary", "payload": { "column1": "Y", "column2": [1, 2, 3], "column3": {} } }, { "type": "Column2 has empty list in list", "payload": { "column1": "Y", "column2": [1, 2, []], "column3": {"A":1} } } ] def isempty(thing): """Recursively scan for emptyness. Return True if emptyness is found in the form of an empty string, list, tuple, set or dictionary.""" if isinstance(thing, str): if not thing: return True elif isinstance(thing, (list, tuple, set)): if not thing: return True for subthing in thing: if isempty(subthing): return True elif isinstance(thing, dict): if not thing: return True for subthing in thing.values(): if isempty(subthing): return True return False for thing in [x for x in a if isempty(x)]: print(thing)

Output:
{'type': 'column1 is empty str', 'payload': {'column1': '', 'column2': [1, 2, 3], 'column3': 1}} {'type': 'column3 is None', 'payload': {'column1': 'Y', 'column2': [1, 2, 3], 'column3': None}} {'type': 'column3 is empty dictionary', 'payload': {'column1': 'Y', 'column2': [1, 2, 3], 'column3': {}}} {'type': 'Column2 has empty list in list', 'payload': {'column1': 'Y', 'column2': [1, 2, []], 'column3': {'A': 1}}}

[python_student]

Sorry to forget that

Error:
TypeError Traceback (most recent call last) <ipython-input-61-8adcda79951d> in <module> 112 payload2 = [] 113 for i in range(len(payload)): --> 114 for value in i['payload'].value(): 115 if value =='': 116 break TypeError: 'int' object is not subscriptable

I had this error

[deanhystad]

That error trace is not for the code you posted.

Your error is dictionary does not have a method named "value", it has "values".

I think you can do this as a one liner. Well two one liners.

if isinstance(payload, list): payload = [d for d in payload if not "" in d["payload"].values()] else: payload = {k:v for k, v in payload.items() if v != ""}

I still think a more generic solution is better.

[python_student]

That error trace is not for the code you posted.

Your error is dictionary does not have a method named "value", it has "values".

I think you can do this as a one liner. Well two one liners.

if isinstance(payload, list): payload = [d for d in payload if not "" in d["payload"].values()] else: payload = {k:v for k, v in payload.items() if v != ""}

I still think a more generic solution is better.

Thank You