Python Learning Note 4

List-Generated

The list generation, which is the comprehensions, is a very simple and powerful build of Python built-in that can be used to create lists.

When we need to create a list that is more complex, you can use that approach.

The format is as follows:l1=[custom expression for x in L2 judgment statement]

Among them, L2 can be the list collection, Dict collection and other forms.

Some examples:

>>> l1=[1, 2, 3, 4, 5, 6]
>>> l2=[x*x for x in L1]
>>> Print L2
[1, 4, 9, 16, 25, 36]

>>> l1=[1, 2, 3, 4, 5, 6]
>>> l2=[x*x for x in L1 if x%2!=0]
>>> Print L2
[1, 9, 25]

Python Learning Note 4