Group list by some rows in Python

December 24, 2023

I have same list of lists

l = [
  ['one'],
  ['', 'any'],
  ['', 'anynay'],
  ['', 'val'],
  ['two'],
  ['', 'dss'],
  ['tr'],
  ['', 'ff'],
  ['', 'mnb']
]

I want get dict group by rows if row[0] not empty

d = {
  'one': [['', 'any'], ['', 'anynay'], ['', 'val']],
  'two': [['', 'dss']],
  'tr': [['', 'ff'], ['', 'mb']]
}

All my attempts is wrong fundamentally

>Solution :

You can simply iterate over the items and add things as they come along. This does however imply that l is strictly in the format described.

d = {}
current = None
for row in l:
    if row[0]:
        # New section starts
        assert len(row) == 1
        assert row[0] not in d
        # Create new list for that key
        d[row[0]] = current = []
    else:
        # Add item to the current list
        current.append(row)