Python defaultdict(list)

>>> s = [('yellow', 1), ('blue', 2), ('yellow', 3), ('blue', 4), ('red', 1)]
>>> d = defaultdict(list)
>>> for k, v in s:
...     d[k].append(v)
...
>>> d.items()
[('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])]

Source: docs.python.org

.defaultdict

>>> from collections import defaultdict
>>> food_list = 'spam spam spam spam spam spam eggs spam'.split()
>>> food_count = defaultdict(int) # default value of int is 0
>>> for food in food_list:
...     food_count[food] += 1 # increment element's value by 1
...
defaultdict(<type 'int'>, {'eggs': 1, 'spam': 7})
>>>

Source: accelebrate.com

Similar codes

0 vote114 views1 answer
How to delete all elements of a list in python
Python
0 vote129 views1 answer
Discord python bot how to change someone's nickname
Python
2 votes54 views1 answer
Select a value randomly in a set python
Python
0 vote144 views1 answer
Discord.py how to print audit logs
Python
3 votes102 views1 answer
How to exit command prompt
Python
5 votes103 views1 answer
Find all files in a directory with extension python
Python
0 vote132 views1 answer
"json" is not defined
Python
1 vote146 views1 answer
Python how to add turtle in tkinter
Python
0 vote140 views1 answer
Django import Response
Python Django
0 vote115 views1 answer
This figure includes axes that are not compatible with tight_layout, so results might be incorrect
Python