在Python 3.6+中，什么是f字符串才能将float 9.9打印为字符串09.90和10输出为10.00？

Question

hHaving looked at three other formatting questions here with tens of answers each I don't see anyone telling how to print a float 9.9 as 09.90 and 10 as 10.00 using the same f-string:

x = 9.9
print(f"{x:02.2f}")  // should print 09.90

x = 10
print(f"{x:02.2f}")  // should print 10.00

The question is what should be in place of :02.2f in the above?

Answer 1

You are looking for

print(f"{x:05.2f}")

The number before the radix point is the total number of characters in the field, not the number to appear before the radix point.

Documentation

Answer 2

f'{x:.2f}'

will print x to two decimal places.

f'{x:05.2f}'

will print x to two decimal places, with five total characters (including the decimal point)