How to round complex number up to 2 decimal points in python?

Question

I want to round the complex and real part upto 2 decimal points. How can I do that in python?

angle = 2 * np.pi *2 
c1 = complex(np.cos(angle),np.sin(angle))
c1 = round(c1,2)

Answer 1

You noted in a comment:

I have t use these complex numbers in a matrix. In order to read it easily I want to display it upto 2 decimal points

So how about modifying the printing of your data, rather than messing with their representation as data? You only need to set_printoptions with a formatter for complex numbers:

>>> import numpy as np

>>> arr = np.random.rand(3,3) + 1j*np.random.rand(3,3)
... print(arr)
[[0.44078748+0.29907718j 0.79358223+0.02234568j 0.20919567+0.34527526j]
 [0.05402969+0.24115898j 0.20941358+0.55299497j 0.29743888+0.32179154j]
 [0.60174937+0.9542182j  0.47197093+0.9202769j  0.41205623+0.27288905j]]

>>> np.set_printoptions(formatter={'complex_kind': '{:.2f}'.format})

>>> print(arr)
[[0.44+0.30j 0.79+0.02j 0.21+0.35j]
 [0.05+0.24j 0.21+0.55j 0.30+0.32j]
 [0.60+0.95j 0.47+0.92j 0.41+0.27j]]

Answer 2

I think you can use the around function from numpy:

import numpy

x= complex(1.2345, 1.2345)
numpy.around(x, 2)
# (1.23+1.23j)

Answer 3

对于紧凑输出：

np.set_printoptions(precision=2, suppress=True)