Printing 2 numbers before comma

Question

I want to print numbers with precision to 2 digits before dot and 3 after.

Example:

1232.352232  
9.1

will show:

32.352  
09.100

I know that

print "%.3f" % 32.352

will show me 3 digits after dot but how to get 2 digits before dot with 0 if that is shorter than 2 digits?

Also http://stackoverflow.com/questions/8885663/how-to-format-a-floating-number-to-fixed-width-in-python — James Jenkinson, Oct 29 '14 at 19:40

Martijn Pieters · Accepted Answer · 2018-06-22T14:09:50.463

6

You can specify a total width for the output; if you include a leading 0 then the number will be padded with zeros to match that minimum width:

"%06.3f" % float_number

Demo:

>>> for float_number in (1232.352232, 9.1):
...     print "%06.3f" % float_number
... 
1232.352
09.100

Note that the number is a minimum width! If you need to truncate the floating point number itself, you'll need to use slicing:

("%06.3f" % float_number)[-6:]

This will truncate string to remove characters from the start if longer than 6:

>>> for float_number in (1232.352232, 9.1):
...     print ("%06.3f" % float_number)[-6:]
... 
32.352
09.100

You may want to look at the format() function too; this function lets you apply the same formatting syntax as the str.format() formatting method and formatted string literals; the syntax is basically the same for floats:

>>> for float_number in (1232.352232, 9.1):
...     formatted = format(float_number, '06.3f')
...     print(formatted[-6:], formatted)
...
32.352 1232.352
09.100 09.100

edited Jun 22 '18 at 14:09

answered Oct 29 '14 at 19:37

Martijn Pieters

1,048,767
296
4,058
3,343

I tried to put "%02.3f" %1.1234 and it doesn't return me 01,123 – Sebastian B Oct 29 '14 at 19:47
@SebastianB: that's because the first number must be set to the *total* width. Include the decimals! `"%06.3f" % 1.1234` works. – Martijn Pieters Oct 29 '14 at 19:48
Is there a concise way to save this to a string variable? – Aaron Robeson Jun 21 '18 at 23:38
@Aaronrobeson: I'm not sure what you mean. The `str % ...` operation returns a new string object, just assign that new object to a variable. – Martijn Pieters Jun 22 '18 at 13:20

score 0 · Answer 2 · answered Oct 29 '14 at 19:45

0

x = "9,1"

def displayNum(num):
    f,s = num.strip().split(',')
    f = '0'*(2-len(f))+f if len(f) < 2 else f[-2:]
    s = s + '0'*(3-len(s)) if len(s) < 3 else s[:3]
    return ",".join([f,s])

print(displayNum(x))

09,100

answered Oct 29 '14 at 19:45

galaxyan

5,944
2
19
43

Printing 2 numbers before comma

2 Answers2