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 vote178 views1 answer
Anaconda-navigator command not found
Python
0 vote195 views4 answers
Convert from python to curl
Python
0 vote180 views6 answers
Gcd
Python
0 vote189 views1 answer
Python selenium class
Python
0 vote190 views1 answer
Printing a varible with a varible. python
Python
0 vote281 views2 answers
Flask rest api upload image
Python
1 vote319 views1 answer
Batchnorm1d pytorch
Python
0 vote221 views1 answer
Add multiple columns to dataframe if not exist pandas
Python
0 vote219 views1 answer
Python request post with json with headers
Python
3 votes186 views1 answer
Python copy a dictionary to a new variable
Python