Question

I have a list or lists in python similar to the following:

[
['name1',value2],
['name2',value3],
['name3',value4],
['name4',value4],
['name5',value5],
['name6',value2],
['name7',value2],
['name8',value4]
]

I want to remove any list within the list that has more than 2 duplicates from the ‘value’ field. The resulting list would look like:

[
['name1',value2],
['name2',value3],
['name3',value4],
['name4',value4],
['name5',value5],
['name6',value2]
]

Edit:

I didn’t think this would be a problem so kept it simple for a clear question, but i actually have four values and not two in each internal list. I.E:

[
['name1',value2,'something','else'],
['name2',value3,'something','else'],
['name3',value4,'something','else'],
['name4',value4,'something','else'],
['name5',value5,'something','else'],
['name6',value2,'something','else']
]

Ashwini Chaudhary’s answer works perfectly but only returns the two first element and not all four… my fault for not adding the complete details. Lesson learned!

Answer 1

if order doesn’t matters:

In [14]: lis=[
['name1','value2','something','else'],
['name2','value3','something','else'],
['name3','value4','something','else'],
['name4','value4','something','else'],
['name5','value5','something','else'],
['name6','value2','something','else']
]

In [22]: dic={}

In [23]: for x in lis:
    dic.setdefault(x[1],[]).append([x[0]]+x[2:])
   ....:     
   ....:     

In [25]: dic
Out[25]: 
{'value2': [['name1', 'something', 'else'], ['name6', 'something', 'else']],
 'value3': [['name2', 'something', 'else']],
 'value4': [['name3', 'something', 'else'], ['name4', 'something', 'else']],
 'value5': [['name5', 'something', 'else']]}

In [27]: [[y[0]]+[x]+y[1:] for x in dic for y in dic[x][:2]]
Out[27]: 
[['name5', 'value5', 'something', 'else'],
 ['name3', 'value4', 'something', 'else'],
 ['name4', 'value4', 'something', 'else'],
 ['name2', 'value3', 'something', 'else'],
 ['name1', 'value2', 'something', 'else'],
 ['name6', 'value2', 'something', 'else']]