raw_list = [["百度", "CPY"], ["京東", "CPY"], ["黃軒", "PN"], ["百度", "CPY"]]

In [8]: new_list = [list(t) for t in set(tuple(_) for _ in raw_list)]
In [9]: new_list
Out[9]: [['京東', 'CPY'], ['百度', 'CPY'], ['黃軒', 'PN']]

In [10]: s = set(tuple(_) for _ in raw_list)
In [11]: s
Out[11]: {('京東', 'CPY'), ('百度', 'CPY'), ('黃軒', 'PN')}

sort(*, key=None, reverse=False)

This method sorts the list in place, using only < comparisons between 
items. Exceptions are not suppressed - if any comparison operations  
fail, the entire sort operation will fail (and the list will likely be left in a 
 partially modified state).

 [`sort()`](https://docs.python.org/3/library/stdtypes.html?highlight=sort#list.sort "list.sort") 

accepts two arguments that can only be passed by keyword ( [keyword-only arguments](https://docs.python.org/3/glossary.html#keyword-only-parameter) ):

key specifies a function of one argument that is used to extract a 
comparison key from each list element (for example, key=str.lower). 
 The key corresponding to each item in the list is calculated once and  then used for the entire sorting process. The default value of None 
means that list items are sorted directly without calculating a separate
 key value.

In [13]: new_list.sort(key=raw_list.index)
In [14]: new_list
Out[14]: [['百度', 'CPY'], ['京東', 'CPY'], ['黃軒', 'PN']]