I have a list with floating point number named a. When I print the list with print a. I get the result as follows.
[8.364, 0.37, 0.09300000000000003, 7.084999999999999, 0.469, 0.303, 9.469999999999999, 0.28600000000000003, 0.2290000000
000001, 9.414, 0.9860000000000001, 0.534, 2.1530000000000005]
Can I tell the list printer to print the format of "5.3f" to get better result?
[8.364, 0.37, 0.093, 7.084, 0.469, 0.303, 9.469, 0.286, 0.229, 9.414, 0.986, 0.534, 2.153]
In [4]: print ['%5.3f' % val for val in l]
['8.364', '0.370', '0.093', '7.085', '0.469', '0.303', '9.470', '0.286', '0.229', '1.000', '9.414', '0.986', '0.534', '2.153']
where l is your list.
edit: If the quotes are an issue, you could use
In [5]: print '[' + ', '.join('%5.3f' % v for v in l) + ']'
[8.364, 0.370, 0.093, 7.085, 0.469, 0.303, 9.470, 0.286, 0.229, 1.000, 9.414, 0.986, 0.534, 2.153]
* before the list's opening bracket [ i.e. print(*['%5.3f' % val for val in l]) which yields a very nice output without quotes ' nor brackets [ ]. Perhaps you would like to add this to your answer?If you need this to work in nested structures, you should look into the pprint module. The following should do what you want, in this context:
from pprint import PrettyPrinter
class MyPrettyPrinter(PrettyPrinter):
def format(self, object, context, maxlevels, level):
if isinstance(object, float):
return ('%.2f' % object), True, False
else:
return PrettyPrinter.format(self, object, context,
maxlevels, level)
print MyPrettyPrinter().pprint({1: [8, 1./3, [1./7]]})
# displays {1: [8, 0.33, [0.14]]}
For more details on pprint, see: http://docs.python.org/library/pprint.html
If it's just for a flat list, then aix's solution is good. Or if you don't like the extra quotes, you could do:
print '[%s]' % ', '.join('%.3f' % val for val in list)
Lovely code, Edward, but doesn't work for me. Output:
{1: [8, 0.3333333333333333, [0.14285714285714285]]}
A breakpoint on the line after isinstance(float) triggers ONLY if I feed pprint a single float.
Python 3.9 on Windows 10, run under VS Code 1.50.1
