How to print floating point numbers as it is without any truncation in python?

Question

I have some number 0.0000002345E^-60. I want to print the floating point value as it is. What is the way to do it? print %f truncates it to 6 digits. Also %n.nf gives fixed

Answer 1

Like this?

>>> print('{:.100f}'.format(0.0000002345E-60))
0.0000000000000000000000000000000000000000000000000000000000000000002344999999999999860343602938602754

As you might notice from the output, it’s not really that clear how you want to do it. Due to the float representation you lose precision and can’t really represent the number precisely. As such it’s not really clear where you want the number to stop displaying.

Also note that the exponential representation is often used to more explicitly show the number of significant digits the number has.

You could also use decimal to not lose the precision due to binary float truncation:

>>> from decimal import Decimal
>>> d = Decimal('0.0000002345E-60')
>>> p = abs(d.as_tuple().exponent)
>>> print(('{:.%df}' % p).format(d))
0.0000000000000000000000000000000000000000000000000000000000000000002345