/Python/Append to a ldictionary value list

Append to a ldictionary value list

#list.append returns None, since it is an in-place operation and you are 
#assigning it back to dic[key]. So, the next time when you do 
#dic.get(key, []).append you are actually doing None.append. 
#That is why it is failing. Instead, you can simply do
dates_dict.setdefault(key, []).append(date)
#or 
from collections import defaultdict
dates_dict = defaultdict(list)
for key, date in cur:
    dates_dict[key].append(date)

Source: stackoverflow.com

Similar codes

0 vote211 views1 answer
Python console ending multiline input
Python
1 vote207 views1 answer
How to find ip address of website using python
Python
0 vote192 views1 answer
Opencv export image
Python
9 votes196 views2 answers
Python get image dimensions
Python
2 votes184 views1 answer
Pandas index false print
Python
1 vote194 views1 answer
Figsize param in pandas plot
Python
0 vote215 views1 answer
Pathlib is symbolic link
Python
0 vote214 views1 answer
Python put console window on top
Python
5 votes149 views1 answer
Python multi split
Python
0 vote171 views1 answer
Run a python script with python and catch command line output
Python