How can I format a decimal to always show 2 decimal places?

Question

I want to display:

49 as 49.00

and:

54.9 as 54.90

Regardless of the length of the decimal

Answer 1

You can use the string formatting operator as so:

num = 49
x = "%.2f" % num  # x is now the string "49.00"

I'm not sure what you mean by "efficient" -- this is almost certainly not the bottleneck of your application. If your program is running slowly, profile it first to find the hot spots, and then optimize those.