In the Code Style chapter examples -Short Ways to Manipulate Lists there is an example "Add three to all list members."

"bad"

foriinrange(len(a)):a[i]+=3

"good"

a= [i+3foriina]

Unfortunately the "bad" and "good" examples do a different things:

• "bad" modifies the original list in place
• "good" creates a new modified list and does not change the original object - not exactly "Add three to all list members."

Although the "good" code looks cleaner the result could be unwanted for example in case of huge lists or required side-effect of modifying the original list. The code at least needs an explanation.