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How do I format a floating number to a fixed width with the following requirements:
- Leading zero if n < 1
- Add trailing decimal zero(s) to fill up fixed width
- Truncate decimal digits past fixed width
- Align all decimal points
For example:
% formatter something like '{:06}'
numbers = [23.23, 0.123334987, 1, 4.223, 9887.2]
for number in numbers:
print formatter.format(number)
The output would be like
23.2300
0.1233
1.0000
4.2230
9887.2000
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 thexas the only argument. - The
10.4fpart after the colon is the format specification. - The
fdenotes fixed-point notation. - The
10is the total width of the field being printed, lefted-padded by spaces. - The
4is the number of digits after the decimal point.
Answer #2:
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 #3:
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 #4:
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 #5:
You can also left pad with zeros. For example if you want number to have 9 characters length, left padded with zeros use:
print('{:09.3f}'.format(number))
Thus, if number = 4.656, the output is: 00004.656
For your example the output will look like this:
numbers = [23.2300, 0.1233, 1.0000, 4.2230, 9887.2000]
for x in numbers:
print('{:010.4f}'.format(x))
prints:
00023.2300
00000.1233
00001.0000
00004.2230
09887.2000
One example where this may be useful is when you want to properly list filenames in alphabetical order. I noticed in some linux systems, the number is: 1,10,11,..2,20,21,…
Thus if you want to enforce the necessary numeric order in filenames, you need to left pad with the appropriate number of zeros.
Answer #6:
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 #7:
This will print 76.66:
print("Number: ", f"{76.663254: .2f}")
Answer #8:
I needed something similar for arrays. That helped me
some_array_rounded=np.around(some_array, 5)
