Python Language Float formatting


Example

>>> '{0:.0f}'.format(42.12345)
'42'

>>> '{0:.1f}'.format(42.12345)
'42.1'

>>> '{0:.3f}'.format(42.12345)
'42.123'

>>> '{0:.5f}'.format(42.12345)
'42.12345'

>>> '{0:.7f}'.format(42.12345)
'42.1234500'

Same hold for other way of referencing:

>>> '{:.3f}'.format(42.12345)
'42.123'

>>> '{answer:.3f}'.format(answer=42.12345)
'42.123'

Floating point numbers can also be formatted in scientific notation or as percentages:

>>> '{0:.3e}'.format(42.12345)
'4.212e+01'

>>> '{0:.0%}'.format(42.12345)
'4212%'

You can also combine the {0} and {name} notations. This is especially useful when you want to round all variables to a pre-specified number of decimals with 1 declaration:

>>> s = 'Hello'
>>> a, b, c = 1.12345, 2.34567, 34.5678
>>> digits = 2

>>> '{0}! {1:.{n}f}, {2:.{n}f}, {3:.{n}f}'.format(s, a, b, c, n=digits)
'Hello! 1.12, 2.35, 34.57'