Formatting Complex Numbers

Question

For a project in one of my classes we have to output numbers up to five decimal places.It is possible that the output will be a complex number and I am unable to figure out

Answer 1

Neither String Formatting Operations - i.e. the modulo (%) operator) - nor the newer str.format() Format String Syntax support complex types. However it is possible to call the __format__ method of all built in numeric types directly. Here is an example:

>>> i = -3 # int
>>> l = -33L # long (only Python 2.X)
>>> f = -10./3 # float
>>> c = - 1./9 - 2.j/9 # complex
>>> [ x.__format__('.3f') for x in (i, l, f, c)]
['-3.000', '-33.000', '-3.333', '-0.111-0.222j']

Note, that this works well with negative imaginary parts too.