I have a function taking float arguments (generally integers or decimals with one significant digit), and I need to output the values in a string with two decimal places (5 -> 5.00, 5.5 -> 5.50, etc). How can I do this in Python?
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python
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floating-point
Using python string formatting.
>>> "%0.2f" % 3
'3.00'
String Formatting:
a = 6.789809823
print('%.2f' %a)
OR
print ("{0:.2f}".format(a))
Round Function can be used:
print(round(a, 2))
Good thing about round() is that, we can store this result to another variable, and then use it for other purposes.
b = round(a, 2)
print(b)
I know it is an old question, but I was struggling finding the answer myself. Here is what I have come up with:
Python 3:
>>> num_dict = {'num': 0.123, 'num2': 0.127}
>>> "{0[num]:.2f}_{0[num2]:.2f}".format(num_dict)
0.12_0.13
If you actually want to change the number itself instead of only displaying it differently use format()
Format it to 2 decimal places:
format(value, '.2f')
example:
>>> format(5.00000, '.2f')
'5.00'
Using Python 3 syntax:
print('%.2f' % number)
String formatting:
print "%.2f" % 5
f-string formatting:
This was new in Python 3.6 - the string is placed in quotation marks as usual, prepended with f'...
in the same way you would r'...
for a raw string. Then you place whatever you want to put within your string, variables, numbers, inside braces f'some string text with a {variable} or {number} within that text'
- and Python evaluates as with previous string formatting methods, except that this method is much more readable.
>>> foobar = 3.141592
>>> print(f'My number is {foobar:.2f} - look at the nice rounding!')
My number is 3.14 - look at the nice rounding!
You can see in this example we format with decimal places in similar fashion to previous string formatting methods.
NB foobar
can be an number, variable, or even an expression eg f'{3*my_func(3.14):02f}'
.
Going forward, with new code I prefer f-strings over common %s or str.format() methods as f-strings can be far more readable, and are often much faster.
Shortest Python 3 syntax:
n = 5
print(f'{n:.2f}')
Since this post might be here for a while, lets also point out python 3 syntax:
"{:.2f}".format(5)
If you want to get a floating point value with two decimal places limited at the time of calling input,
Check this out ~
a = eval(format(float(input()), '.2f')) # if u feed 3.1415 for 'a'.
print(a) # output 3.14 will be printed.
Source: Stackoverflow.com