Python print a float with a given number of digits

Question

I have some floating point values in Python. I would like to print them so that the have the same number of digits (sum of the integer and decimal parts)

For example considering the two numbers:

a = 12.123456
b = 123.1234567

I would like to print their value formatted as follows:

12.1234
123.123

So that they have the same length.

One simple way is the following:

if (val>100):
    print("%0.3f" % val)
else:
    print("%0.4f" % val)

Is there a smarter way to control both the number of integer and decimal digits at the same time in python so that the resulting string is constant?

Solution 1

Ok I thought about this solution that is basically a work-around:

LIM = 7;
a = 12.123456
b = 123.1234567
print(str(a)[:LIM])
print(str(b)[:LIM])

Solution 2

The formating method for both integer and decimal is

>>> '{:06.2f}'.format(3.141592653589793)
'003.14'

the part before the . (6 here) denotes the total length of padding (including the .), and after the . (2fhere) denotes digits after decimal point. Hope it helps. checkout the link.

Solution 3

You can try to do something like this

print('{:.6}'.format(val))

Comments

[Francesco Boi]

Actually it works in most of the cases but not if the integer part is 0: for example it does not work in the case of 0.678923156 because it prints 6 decimals without counting the 0 integer part

[Admin]

it looks a bit scary, but will work for the case with zero at the beginning print(('{:.6}' if int(val) else '{:.5}').format(val)) {:.5} - this will applied if integer part equals zero, in other cases {:.6}