How to format a floating number to fixed width in Python

Question

How do I format a floating number to a fixed width with the following requirements:

1. Leading zero if n < 1
2. Add trailing decimal zero(s) to fill up f

Answer 1

This will print 76.66:

print("Number: ", f"{76.663254: .2f}")

Answer 2

You can also left pad with zeros. For example if you want number to have 9 characters length, left padded with zeros use:

print('{:09.3f}'.format(number))

Thus, if number = 4.656, the output is: 00004.656

For your example the output will look like this:

numbers  = [23.2300, 0.1233, 1.0000, 4.2230, 9887.2000]
for x in numbers: 
    print('{:010.4f}'.format(x))

prints:

00023.2300
00000.1233
00001.0000
00004.2230
09887.2000

One example where this may be useful is when you want to properly list filenames in alphabetical order. I noticed in some linux systems, the number is: 1,10,11,..2,20,21,...

Thus if you want to enforce the necessary numeric order in filenames, you need to left pad with the appropriate number of zeros.