Basically, you create a Function interface: and then pass in an anonymous subclass to your method. Your method could either apply the function to each element in-place: or create a new List (basically creating a mapping from the input list to the output list): Which one is preferable depends on your use case. If your … Read more
The syntax a if b else c is a ternary operator in Python that evaluates to a if the condition b is true – otherwise, it evaluates to c. It can be used in comprehension statements: So for your example,
What you are using is called a list comprehension in Python, not an inline for-loop (even though it is similar to one). You would write your loop as a list comprehension like so: When using a list comprehension, you do not call list.append because the list is being constructed from the comprehension itself. Each item … Read more
You can use a generator expression: but parentheses were already taken for … generator expressions.
You can use a generator expression: but parentheses were already taken for … generator expressions.
I believe the syntax you were looking for is as follows: Alternately, for python <= 2.7.1, you want:
Consider the following lists: How to get the following result:
Here is how you would do this with a nested list comprehension: This would give you a list of lists, similar to what you started with except with floats instead of strings. If you want one flat list then you would use [float(y) for x in l for y in x].
You can use a list comprehension: The iterator enumerate(my_list) yields pairs (index, item) for each item in the list. Using i, x as loop variable target unpacks these pairs into the index i and the list item x. We filter down to all x that match our criterion, and select the indices i of these elements.
Do-something if <condition>, else do-something else.