Print Either An Integer Or A Float With N Decimals

In Python, how can one print a number that might be an integer or real type, when the latter case would require me to limit my printout to a certain amount of digits? Long story sh

Solution 1:

With Python 3*, you can just use round() because in addition to rounding floats, when applied to an integer it will always return an int:

>>> num = 1.2345
>>> round(num,3)
1.234
>>> num = 1
>>> round(num,3)
1

This behavior is documented in help(float.__round__):

Help on method_descriptor:

__round__(...)
    Return the Integral closest to x, rounding half toward even.
    When an argument is passed, work like built-in round(x, ndigits).

And help(int.__round__):

Help on method_descriptor:

__round__(...)
    Rounding an Integral returns itself.
    Rounding with an ndigits argument also returns an integer.

* With Python 2, round() always returns a float.

Solution 2:

If you need to maintain a fixed-width for float values, you could use the printf-style formatting, like this:

>>> num = 1
>>> print('%0.*f' % (isinstance(num, float) * 3, num))
1
>>> num = 1.2345
>>> print('%0.*f' % (isinstance(num, float) * 3, num))
1.234
>>> num = 1.2
>>> print('%0.*f' % (isinstance(num, float) * 3, num))
1.200

Solution 3:

If you use a fix number of floating point, you could just use a replace to remove the extra 0. For instance this would do the trick:

print("{:.3f}".format(1).replace(".000", ""))

Solution 4:

For fix number of decimal point:

>>> num = 0.2
>>> print('%.04*f' % num)
0.2000

>>> num = 3.102
>>> print('%.02*f' % num)
3.10