If statement in list dynamic creation
Question:
colors = [ (i % 2 == 0)? "W" else "B" for i in range(4000)]
The above is an invalid python syntax. But you get the goal, colors should be ["W", "B", "W",…] 4000 times.
If there a way to achieve this in a single line in python ?
Answers:
You were close. You just didn’t have the syntax quite right. Here’s what you want:
colors = [ "W" if (i % 2 == 0) else "B" for i in range(4000)]
Result:
['W', 'B', 'W', 'B', 'W', 'B', 'W', 'B' ....
If you are going to iterate over the colors rather than really needing them all at once in an in-memory list, using a generator is better for both speed and memory consumption…
for color in ("W" if (i % 2 == 0) else "B" for i in range(20)):
...
colors = [ (i % 2 == 0)? "W" else "B" for i in range(4000)]
The above is an invalid python syntax. But you get the goal, colors should be ["W", "B", "W",…] 4000 times.
If there a way to achieve this in a single line in python ?
You were close. You just didn’t have the syntax quite right. Here’s what you want:
colors = [ "W" if (i % 2 == 0) else "B" for i in range(4000)]
Result:
['W', 'B', 'W', 'B', 'W', 'B', 'W', 'B' ....
If you are going to iterate over the colors rather than really needing them all at once in an in-memory list, using a generator is better for both speed and memory consumption…
for color in ("W" if (i % 2 == 0) else "B" for i in range(20)):
...