How to format a floating number to fixed width in Python

Question

How do I format a floating number to a fixed width with the following requirements:

1. Leading zero if n < 1
2. Add trailing decimal zero(s) to fill up f

Answer 1

for x in numbers:
    print "{:10.4f}".format(x)

prints

   23.2300
    0.1233
    1.0000
    4.2230
 9887.2000

The format specifier inside the curly braces follows the Python format string syntax. Specifically, in this case, it consists of the following parts:

• The empty string before the colon means "take the next provided argument to format()" – in this case the x as the only argument.
• The 10.4f part after the colon is the format specification.
• The f denotes fixed-point notation.
• The 10 is the total width of the field being printed, lefted-padded by spaces.
• The 4 is the number of digits after the decimal point.

Answer 2

In python3 the following works:

>>> v=10.4
>>> print('% 6.2f' % v)
  10.40
>>> print('% 12.1f' % v)
        10.4
>>> print('%012.1f' % v)
0000000010.4

Answer 3

See Python 3.x format string syntax:

IDLE 3.5.1   
numbers = ['23.23', '.1233', '1', '4.223', '9887.2']

for x in numbers:  
    print('{0: >#016.4f}'. format(float(x)))  

     23.2300
      0.1233
      1.0000
      4.2230
   9887.2000

Answer 4

It has been a few years since this was answered, but as of Python 3.6 (PEP498) you could use the new f-strings:

numbers = [23.23, 0.123334987, 1, 4.223, 9887.2]

for number in numbers:
    print(f'{number:9.4f}')

Prints:

  23.2300
   0.1233
   1.0000
   4.2230
9887.2000

Answer 5

In Python 3.

GPA = 2.5
print(" %6.1f " % GPA)

6.1f means after the dots 1 digits show if you print 2 digits after the dots you should only %6.2f such that %6.3f 3 digits print after the point.

Answer 6

I needed something similar for arrays. That helped me

some_array_rounded=np.around(some_array, 5)