Add zeros to a float after the decimal point in Python

Question

Format it to 6 decimal places:

format(value, '.6f')

Demo:

>>> format(2.0, '.6f')
'2.000000'

The format() function turns values to strings following the formatting instructions given.

I've tried n ways but nothing worked that way I was wanting in, at last, this worked for me.

foo = 56
print (format(foo, '.1f'))
print (format(foo, '.2f'))
print (format(foo, '.3f'))
print (format(foo, '.5f'))

output:

56.0 
56.00
56.000
56.00000

Meaning that the 2nd argument of format takes the decimal places you'd have to go up to. Keep in mind that format returns string.

From Python 3.6 it's also possible to do f-string formatting. This looks like:

f"{value:.6f}"

Example:

> print(f"{2.0:.6f}")
'2.000000'

An answer using the format() command is above, but you may want to look into the Decimal standard library object if you're working with floats that need to represent an exact value. You can set the precision and rounding in its context class, but by default it will retain the number of zeros you place into it:

>>> import decimal
>>> x = decimal.Decimal('2.0000')
>>> x
Decimal('2.0000')
>>> print x
2.0000
>>> print "{0} is a great number.".format(x)
2.0000 is a great number.