/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

4 votes191 views2 answers
Matplotlib plot title font size
Python
1 vote182 views1 answer
Get attribute in selenium python
Python
2 votes190 views5 answers
Download python 3.6 64 bit for windows 7
Python
2 votes203 views1 answer
Django model current timestamp
Python
0 vote231 views1 answer
Seconds to time python
Python
74 votes273 views3 answers
Python find in list
Python
1 vote207 views2 answers
Linspace python
Python
1 vote150 views1 answer
User input python
Python
0 vote202 views1 answer
Python convert dict to xml
Python
0 vote247 views1 answer
Django 2.2 disable cache settings.STATIC_URL
Python Django