如果Python中的数字是实数，如何不显示虚部（0j）？

Question

我想显示数字，这样如果数字是实数，则只显示实部。 （不要显示

0j

）
如果是虚数，则仅显示虚部。 如果很复杂，则显示实部和虚部。

代码输出为：

k = 251.50+0.00j  
fc0 = 0.00 GHz, beta_n0 = 251.50+0.00j, dist = 3.98+0.00j mm  
fc1 = 9.99 GHz, beta_n1 = 139.24+0.00j, dist = 7.18+0.00j mm  
fc2 = 19.99 GHz, beta_n2 = 0.00+334.97j, dist = 0.00-2.99j mm  
fc3 = 29.98 GHz, beta_n3 = 0.00+575.79j, dist = 0.00-1.74j mm  

但我想要这样的东西：

k = 251.50  
fc0 = 0.00 GHz, beta_n0 = 251.50, dist = 3.98 mm  
fc1 = 9.99 GHz, beta_n1 = 139.24, dist = 7.18 mm  
fc2 = 19.99 GHz, beta_n2 = 334.97j, dist = -2.99j mm  
fc3 = 29.98 GHz, beta_n3 = 575.79j, dist = -1.74j mm 

有没有简单的方法可以做到这一点？

代码如下。

import numpy as np
from scipy.constants import c, mu_0, epsilon_0, pi
from cmath import sqrt

c0 = c
eps0 = epsilon_0
mi0 = mu_0

d = 1.5e-2
f = 12e9
eps_r_ = 1
eps_r__ = 0  #2e-3
mi_r = 1

cc = c0/sqrt(eps_r_*mi_r)
k = 2*pi*f/cc

print("k = {0:.2f}".format(k))

for n in range(4):
    fc = n*c0/(2*d)
    beta_n = sqrt((k**2-(n*pi/d)**2))
    print("fc{0} = {1:.2f} GHz, beta_n{0} = {2:.2f}, dist = {3:.2f} mm".format(n,fc*1e-9,beta_n,1/beta_n*1e3))

Answer 1

您可以继承

complex

类型：

In [1]: class MyComplex(complex):
   ...:     def __repr__(self):
   ...:         if self.imag == 0:
   ...:             return str(self.real)
   ...:         elif self.real == 0:
   ...:             return str(self.imag) + 'j'
   ...:         else:
   ...:             return super(MyComplex, self).__repr__()
   ...:
In [2]: MyComplex(0)
Out[2]: 0.0

In [3]: MyComplex(0+0j)
Out[3]: 0.0

In [4]: MyComplex(1+0j)
Out[4]: 1.0

In [5]: MyComplex(1j)
Out[5]: 1.0j

In [6]: MyComplex(1+1j)
Out[6]: (1+1j)

Answer 2

这个怎么样，

dist = 3.98+0.00j
print(np.real_if_close(dist))
# 3.98
dist = -2.99j
print(np.real_if_close(dist))
# (-0-2.99j)

以上是默认的

tol=100

，可以在https://numpy.org/devdocs/reference/ generated/numpy.real_if_close.html

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